Release v1.15.8

Resolves #13462

When a url string is schema less and the host is followed by a colon
without setting the actual port, `:uri_string.parse/1` returns the
port to be `:undefined`. As long as the url string is parseable,
we should translate `:undefined` to `nil`, in order to ensure we return
a valid URI struct.

.github/workflows/builds.hex.pm.yml

@@ -30,7 +30,7 @@ jobs:
           - otp: 26
             otp_version: '26.0'
             build_docs: build_docs
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
         with:

.github/workflows/release.yml

@@ -15,7 +15,7 @@ permissions:
 
 jobs:
   create_draft_release:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
@@ -40,7 +40,7 @@ jobs:
           - otp: 26
             otp_version: '26.0'
             build_docs: build_docs
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
       - uses: actions/checkout@v3
         with:
@@ -56,7 +56,9 @@ jobs:
         run: |
           gh release upload --clobber "${{ github.ref_name }}" \
             elixir-otp-${{ matrix.otp }}.zip \
-            elixir-otp-${{ matrix.otp }}.zip.sha{1,256}sum
+            elixir-otp-${{ matrix.otp }}.zip.sha{1,256}sum \
+            elixir-otp-${{ matrix.otp }}.exe \
+            elixir-otp-${{ matrix.otp }}.exe.sha{1,256}sum
       - name: Upload Docs to GitHub
         if: ${{ matrix.build_docs }}
         env:

.github/workflows/release_pre_built/action.yml

@@ -22,6 +22,20 @@ runs:
         shasum -a 1 elixir-otp-${{ inputs.otp }}.zip > elixir-otp-${{ inputs.otp }}.zip.sha1sum
         shasum -a 256 elixir-otp-${{ inputs.otp }}.zip > elixir-otp-${{ inputs.otp }}.zip.sha256sum
         echo "$PWD/bin" >> $GITHUB_PATH
+    - name: Install NSIS
+      shell: bash
+      run: |
+        sudo apt update
+        sudo apt install -y nsis
+    - name: Build Elixir Windows Installer
+      shell: bash
+      run: |
+        export OTP_VERSION=${{ inputs.otp_version }}
+        export ELIXIR_ZIP=$PWD/elixir-otp-${{ inputs.otp }}.zip
+        (cd lib/elixir/scripts/windows_installer && ./build.sh)
+        mv lib/elixir/scripts/windows_installer/tmp/elixir-otp-${{ inputs.otp }}.exe .
+        shasum -a 1   elixir-otp-${{ inputs.otp }}.exe > elixir-otp-${{ inputs.otp }}.exe.sha1sum
+        shasum -a 256 elixir-otp-${{ inputs.otp }}.exe > elixir-otp-${{ inputs.otp }}.exe.sha256sum
     - name: Get latest stable ExDoc version
       if: ${{ inputs.build_docs }}
       shell: bash

CHANGELOG.md

@@ -68,12 +68,20 @@ In Elixir v1.15, the new reports will look like:
     error: undefined function foo/0 (there is no such import)
       my_file.exs:1
 
-    ** (CompileError) nofile: cannot compile file (errors have been logged)
+    ** (CompileError) my_file.exs: cannot compile file (errors have been logged)
 
 A new function, called `Code.with_diagnostics/2`, has been added so this
 information can be leveraged by editors, allowing them to point to several
 errors at once.
 
+### Potential incompatibilities
+
+As part of this effort, the behaviour where undefined variables were
+transformed into nullary function calls, often leading to confusing error
+reports, has been disabled during project compilation. You can invoke
+`Code.compiler_options(on_undefined_variable: :warn)` at the top of
+your `mix.exs` to bring the old behaviour back.
+
 ## Integration with Erlang/OTP logger
 
 This release provides additional features such as global logger
@@ -100,61 +108,185 @@ config :logger, :default_formatter,
   format: "$time $message $metadata"
 ```
 
-If you use `Logger.Backends.Console` or other backends, they are
-still fully supported and functional. If you implement your own
-backends, you want to consider migrating to
+If you use `Logger.Backends.Console` with a custom device or other
+backends, they are still fully supported and functional. If you
+implement your own backends, you want to consider migrating to
 [`:logger_backends`](https://github.com/elixir-lang/logger_backends)
 in the long term.
 
 See the new `Logger` documentation for more information on the
 new features and on compatibility.
 
-## v1.15.0-rc.1 (2022-05-29)
+## v1.15.8 (2024-05-21)
+
+### 1. Bug fixes
+
+#### Elixir
+
+  * [bin/elixir] Properly handle the `--dbg` flag in Elixir's CLI
+  * [System] Add a note that arguments are unsafe when invoking .bat/.com scripts on Windows via `System.cmd/3`
+  * [Port] Add a note that arguments are unsafe when invoking .bat/.com scripts on Windows
+  * [URI] Ensure `:undefined` fields are properly converted to `nil` when invoking Erlang's API
+
+#### Logger
+
+  * [Logger] Ensure translators are persisted across logger restarts
+
+#### Mix
+
+  * [mix compile] Ensure compile paths are accessible during compilation
+
+## v1.15.7 (2023-10-14)
 
 ### 1. Enhancements
 
 #### Elixir
 
-  * [File] Support distributed `File.Stream`
-  * [Module] Add `Module.get_last_attribute/3`
-  * [Task] Reduce footprint of tasks by avoiding unecessary work during spawning
+  * [Elixir] Allow code evaluation across Elixir versions
 
-#### ExUnit
+### 2. Bug fixes
 
-  * [ExUnit.Case] Add `ExUnit.Case.get_last_registered_test/1`
+#### EEx
+
+  * [EEx] Do not emit duplicate warnings from tokenizer
+
+#### Mix
+
+  * [mix format] Correctly match file to subdirectory in `Mix.Tasks.Format.formatter_for_file/2`
+
+## v1.15.6 (2023-09-20)
+
+This release also includes fixes to the Windows installer.
+
+### 1. Bug fixes
+
+#### EEx
+
+  * [EEx] Do not crash when printing tokenizer warnings
+
+#### Elixir
+
+  * [Code] Fix formatter for nested `*` in bitstrings
+  * [Code] Improve feedback when an invalid block is given `Code.quoted_to_algebra/2`
+  * [Kernel] Trace functions before they are inlined
+
+#### Mix
+
+  * [mix compile] Ensure `:extra_applications` declare in umbrella projects are loaded
+  * [mix deps.get] Do not check for invalid applications before deps.get
+  * [mix deps.update] Do not check for invalid applications before deps.update
+  * [mix format] Load plugins when invoking the formatter from an IDE
+
+## v1.15.5 (2023-08-28)
+
+### 1. Enhancements
+
+#### IEx
+
+  * [IEx.Autocomplete] Speed up loading of struct suggestions
 
 ### 2. Bug fixes
 
 #### Elixir
 
-  * [Code] Ensure `:on_undefined_variable` option works as advertised (regression)
-  * [Code] Format paths in `Code.with_diagnostic/2` as relative paths (regression)
-  * [Kernel] Raise when macros are given to dialyzer
-  * [Kernel] Support bitstring specifiers as map keys in pattern (regression)
-  * [Module] Ensure that `Module.get_attribute/3` returns `nil` and not the given default value when an attribute has been explicitly set as `nil`
-  * [Task] Do not double log Task failure reports
+  * [Code.Fragment] Fix `Code.Fragment.surround_context/2` for aliases and submodules of non-aliases
+  * [Kernel] Ensure stacktrace is included when necessary when rescuing multiple exceptions in the same branch
+  * [Kernel] Fix index in error message for unused optional arguments
 
 #### ExUnit
 
-  * [ExUnit.CaptureLog] Allow capturing deprecated log level (regression)
-  * [ExUnit.DocTest] Ensure proper line is returned when failing to parse doctest results
+  * [ExUnit.Diff] Fix scenario where diff would not show up due to a timed-out loop
 
 #### IEx
 
-  * [IEx] Fix IO operations not returning when booting IEx (regression)
+  * [IEx] Force group leader to run as a binary and unicode in IEx
 
 #### Mix
 
-  * [mix deps] Ensure dependencies with `included_applications` can be loaded (regression)
-  * [mix format] Ensure proper formatter options are returned for files (regression)
+  * [mix compile] Do not assume `blake` is always available
+  * [mix format] Load and compile plugins if specified in subdirectories
 
-### 3. Soft deprecations
+## v1.15.4 (2023-07-18)
+
+### 1. Bug fixes
+
+#### Mix
+
+  * [mix archive.build] Disable protocol consolidation when building archives on archive.install
+  * [mix compile] Track removed files per local dependency (this addresses a bug where files depending on modules from path dependencies always recompiled)
+  * [mix release] Do not strip relevant chunks from Erlang/OTP 26
+
+## v1.15.3 (2023-07-15)
+
+### 1. Enhancements
 
 #### Elixir
 
-  * [Kernel] Require pin variable when accessing variable inside binary size in match
+  * [Kernel] Improve stacktraces when executing unnested Elixir code in a file
 
-## v1.15.0-rc.0 (2022-05-22)
+#### Mix
+
+  * [Mix] Allow to opt-out of starting apps in `Mix.install/2`
+
+### 2. Bug fixes
+
+#### Elixir
+
+  * [Code] Ensure `with_diagnostics` propagate warnings from inner Erlang passes
+
+#### IEx
+
+  * [IEx] Fix `--remsh` on Erlang/OTP 25 and earlier
+
+#### Mix
+
+  * [mix compile.elixir] Ensure `__mix_recompile__?` callbacks are properly invoked
+
+## v1.15.2 (2023-07-01)
+
+### 1. Bug fixes
+
+#### IEx
+
+  * [IEx] Fix CLI being unable to boot on Windows
+
+## v1.15.1 (2023-06-30)
+
+### 1. Enhancements
+
+  * [Code] `Code.string_to_quoted/2` honors `:static_atoms_encoder` for multi-letter sigils
+
+### 2. Bug fixes
+
+#### ExUnit
+
+  * [ExUnit.CaptureLog] Fix race condition on concurrent `capture_log`
+  * [ExUnit.CaptureLog] Respect options passed to nested `capture_log` calls
+  * [ExUnit.Doctest] Properly compile doctests without results terminated by fences
+  * [ExUnit.Doctest] Allow variables defined in doctests to be used in expectation
+
+#### IEx
+
+  * [IEx] Ensure `pry` works on Erlang/OTP 25 and earlier while IEx is booting
+  * [IEx] `Code.Fragment.surround_context` considers surround context around spaces and parens
+
+#### Logger
+
+  * [Logger] Do not assume Logger has been loaded at compile-time
+  * [Logger.Formatter] Properly handle `:function` as metadata
+
+#### Mix
+
+  * [mix compile] Ensure the current project is available on the code path after its Elixir sources are compiled
+  * [mix compile] Guarantee yecc/leex are available when emitting warnings from previous runs
+  * [mix compile] Fix bug where an external resource was deleted after its
+  mtime was successfully retrieved
+  * [mix compile] Track removed modules and exports across local deps
+  * [mix deps] Fix an issue where dependencies could not be started in an umbrella projects
+  * [mix release] Properly handle optional dependencies when there is a conflict in the application start mode
+  * [mix release] Remove `--werl` from release scripts on Erlang/OTP 26
+
+## v1.15.0 (2023-06-19)
 
 ### 1. Enhancements
 
@@ -175,6 +307,7 @@ new features and on compatibility.
   * [Date] Add `Date.before?/2` and `Date.after?/2`
   * [DateTime] Add `DateTime.before?/2` and `DateTime.after?/2`
   * [DateTime] Support precision in `DateTime.utc_now/2`
+  * [File] Support distributed `File.Stream`
   * [Inspect] `Inspect` now renders `'charlists'` as `~c"charlists"` by default
   * [Kernel] Break down `case` and `cond` inside `dbg/2`
   * [Kernel] Add `t:nonempty_binary/0` and `t:nonempty_bitstring/0`
@@ -195,6 +328,8 @@ new features and on compatibility.
   * [NaiveDateTime] Add `NaiveDateTime.beginning_of_day/1` and `NaiveDateTime.end_of_day/1`
   * [NaiveDateTime] Add `NaiveDateTime.before?/2` and `NaiveDateTime.after?/2`
   * [NaiveDateTime] Support precision in `NaiveDateTime.utc_now/2`
+  * [Module] Mark functions as generated in "Docs" chunk
+  * [Module] Add `Module.get_last_attribute/3`
   * [OptionParser] Support `:return_separator` option
   * [Process] Add `Process.alias/0,1` and `Process.unalias/1`
   * [Range] Add `Range.split/2`
@@ -204,6 +339,7 @@ new features and on compatibility.
   * [System] Support `:lines` in `System.cmd/3` to capture output line by line
   * [Task] Remove head of line blocking on `Task.yield_many/2`
   * [Task] Enable selective receive optimizations in Erlang/OTP 26+
+  * [Task] Reduce tasks footprint by avoiding unecessary work during spawning
   * [Task.Supervisor] Do not copy args on temporary `Task.Supervisor.start_child/2`
   * [Time] Add `Time.before?/2` and `Time.after?/2`
   * [URI] Add `URI.append_path/2`
@@ -212,7 +348,9 @@ new features and on compatibility.
 
   * [ExUnit] Add more color configuration to ExUnit CLI formatter
   * [ExUnit.Callbacks] Accept `{module, function}` tuples in ExUnit `setup` callbacks
+  * [ExUnit.Case] Add `ExUnit.Case.get_last_registered_test/1`
   * [ExUnit.Doctest] Add `ExUnit.DocTest.doctest_file/2`
+  * [ExUnit.Doctest] Include `doctest_data` in doctest tags
   * [ExUnit.Formatter] When comparing two anonymous functions, defined at the same place but capturing a different environment, we will now also diff the environments
 
 #### IEx
@@ -267,16 +405,22 @@ new features and on compatibility.
   * [Kernel] Expand macros on the left side of -> in `try/rescue`
   * [Kernel] Raise on misplaced `...` inside typespecs
   * [Kernel] Do not import `behaviour_info` and `module_info` functions from Erlang modules
+  * [Kernel] Raise when macros are given to dialyzer
   * [Kernel.ParallelCompiler] Make sure compiler doesn't crash when there are stray messages in the inbox
   * [Kernel.ParallelCompiler] Track compile and runtime warnings separately
+  * [Module] Ensure that `Module.get_attribute/3` returns `nil` and not the given default value when an attribute has been explicitly set as `nil`
   * [System] Fix race condition when a script would terminate before `System.stop/1` executes
+  * [Task] Do not double log Task failure reports
   * [URI] Make sure `URI.merge/2` works accordingly with relative paths
 
 #### ExUnit
 
   * [ExUnit] Fix crash when `@tag capture_log: true` was set to true and the Logger application was shut down in the middle of the test
   * [ExUnit] Do not merge context as tags inside the runner to reduce memory usage when emitting events to formatters
+  * [ExUnit] Mark test cases as invalid when an exit occurs during `setup_all`
   * [ExUnit] Do not expand or collect vars from quote in ExUnit assertions
+  * [ExUnit.DocTest] Ensure proper line is returned when failing to parse doctest results
+  * [ExUnit.Doctest] Fix line information when a doctest with multiple assertions fails
 
 #### IEx
 
@@ -288,6 +432,7 @@ new features and on compatibility.
 
   * [mix compile] Include `cwd` in compiler cache key
   * [mix release] Fix Windows service when invoking `erlsrv.exe` in path with spaces
+  * [mix xref] Raise early if `mix xref` is used at the umbrella root
 
 ### 3. Soft deprecations (no warnings emitted)
 
@@ -295,6 +440,7 @@ new features and on compatibility.
 
   * [File] `File.cp/3` and `File.cp_r/3` with a function as third argument
     is deprecated in favor of a keyword list
+  * [Kernel] Require pin variable when accessing variable inside binary size in match
   * [Kernel.ParallelCompiler] Require the `:return_diagnostics` option to be
     set to true when compiling or requiring code
 

Makefile

@@ -2,7 +2,7 @@ PREFIX ?= /usr/local
 TEST_FILES ?= "*_test.exs"
 SHARE_PREFIX ?= $(PREFIX)/share
 MAN_PREFIX ?= $(SHARE_PREFIX)/man
-#CANONICAL := MAJOR.MINOR/
+CANONICAL := 1.15/
 CANONICAL ?= main/
 DOCS_FORMAT ?= html
 ELIXIRC := bin/elixirc --ignore-module-conflict $(ELIXIRC_OPTS)

RELEASE.md

@@ -14,7 +14,7 @@
 
 6. Copy the relevant bits from /CHANGELOG.md to the GitHub release and publish it
 
-7. Add the release to `elixir.csv` with the minimum supported OTP version (all releases), update `erlang.csv` to the latest supported OTP version, and `_data/elixir-versions.yml` (except for RCs) files in `elixir-lang/elixir-lang.github.com`
+7. Update `_data/elixir-versions.yml` (except for RCs) in `elixir-lang/elixir-lang.github.com`
 
 ## Creating a new vMAJOR.MINOR branch (after first rc)
 

SECURITY.md

@@ -6,12 +6,11 @@ Elixir applies bug fixes only to the latest minor branch. Security patches are a
 
 Elixir version | Support
 :------------- | :-----------------------------
-1.15           | Development
-1.14           | Bug fixes and security patches
+1.15           | Bug fixes and security patches
+1.14           | Security patches only
 1.13           | Security patches only
 1.12           | Security patches only
 1.11           | Security patches only
-1.10           | Security patches only
 
 ## Announcements
 

VERSION

@@ -1 +1 @@
-1.15.0-rc.1
+1.15.8

bin/elixir

@@ -1,7 +1,7 @@
 #!/bin/sh
 set -e
 
-ELIXIR_VERSION=1.15.0-rc.1
+ELIXIR_VERSION=1.15.8
 
 if [ $# -eq 0 ] || { [ $# -eq 1 ] && { [ "$1" = "--help" ] || [ "$1" = "-h" ]; }; }; then
   cat <<USAGE >&2
@@ -94,6 +94,7 @@ starts_with () {
 }
 
 ERL_EXEC="erl"
+MODE="cli"
 I=1
 E=0
 LENGTH=$#
@@ -104,13 +105,17 @@ while [ $I -le $LENGTH ]; do
   S=0
   C=0
   case "$1" in
-    +elixirc|+iex)
+    +elixirc)
         C=1
         ;;
-    -v|--no-halt|--dbg)
+    +iex)
+        C=1
+        MODE="iex"
+        ;;
+    -v|--no-halt)
         C=1
         ;;
-    -e|-r|-pr|-pa|-pz|--eval|--remsh|--dot-iex)
+    -e|-r|-pr|-pa|-pz|--eval|--remsh|--dot-iex|--dbg)
         C=2
         ;;
     --rpc-eval)
@@ -223,12 +228,12 @@ fi
 ERTS_BIN=
 ERTS_BIN="$ERTS_BIN"
 
-set -- "$ERTS_BIN$ERL_EXEC" -noshell -elixir_root "$SCRIPT_PATH"/../lib -pa "$SCRIPT_PATH"/../lib/elixir/ebin $ELIXIR_ERL_OPTIONS -s elixir start_cli $ERL "$@"
+set -- "$ERTS_BIN$ERL_EXEC" -noshell -elixir_root "$SCRIPT_PATH"/../lib -pa "$SCRIPT_PATH"/../lib/elixir/ebin $ELIXIR_ERL_OPTIONS -s elixir start_$MODE $ERL "$@"
 
 if [ -n "$RUN_ERL_PIPE" ]; then
   ESCAPED=""
   for PART in "$@"; do
-    ESCAPED="$ESCAPED $(echo "$PART" | sed 's@[^a-zA-Z0-9_/-]@\\&@g')"
+    ESCAPED="$ESCAPED $(printf '%s' "$PART" | sed 's@[^a-zA-Z0-9_/-]@\\&@g')"
   done
   mkdir -p "$RUN_ERL_PIPE"
   mkdir -p "$RUN_ERL_LOG"

bin/elixir.bat

@@ -1,6 +1,6 @@
 @if defined ELIXIR_CLI_ECHO (@echo on) else (@echo off)
 
-set ELIXIR_VERSION=1.15.0-rc.1
+set ELIXIR_VERSION=1.15.8
 
 setlocal enabledelayedexpansion
 if    ""%1""==""""                if ""%2""=="""" goto documentation
@@ -81,9 +81,6 @@ set beforeExtra=
 rem Option which determines whether the loop is over
 set endLoop=0
 
-rem Designates which mode / Elixir component to run as
-set runMode="elixir"
-
 rem Designates the path to the current script
 set SCRIPT_PATH=%~dp0
 
@@ -106,7 +103,7 @@ if !endLoop! == 1 (
 )
 rem ******* EXECUTION OPTIONS **********************
 if !par!=="--werl"   (set useWerl=1 && goto startloop)
-if !par!=="+iex" (set parsElixir=!parsElixir! +iex && goto startloop)
+if !par!=="+iex"     (set parsElixir=!parsElixir! +iex && set useIEx=1 && goto startloop)
 if !par!=="+elixirc" (set parsElixir=!parsElixir! +elixirc && goto startloop)
 rem ******* EVAL PARAMETERS ************************
 if ""==!par:-e=! (
@@ -164,8 +161,13 @@ reg query HKCU\Console /v VirtualTerminalLevel 2>nul | findstr /e "0x1" >nul 2>n
 if %errorlevel% == 0 (
   set beforeExtra=-elixir ansi_enabled true !beforeExtra!
 )
+if defined useIEx (
+  set beforeExtra=-s elixir start_iex !beforeExtra!
+) else (
+  set beforeExtra=-s elixir start_cli !beforeExtra!
+)
 
-set beforeExtra=-noshell -elixir_root !SCRIPT_PATH!..\lib -pa !SCRIPT_PATH!..\lib\elixir\ebin -s elixir start_cli !beforeExtra!
+set beforeExtra=-noshell -elixir_root "!SCRIPT_PATH!..\lib" -pa "!SCRIPT_PATH!..\lib\elixir\ebin" !beforeExtra!
 
 if defined ELIXIR_CLI_DRY_RUN (
    if defined useWerl (

bin/iex

@@ -30,4 +30,4 @@ readlink_f () {
 
 SELF=$(readlink_f "$0")
 SCRIPT_PATH=$(dirname "$SELF")
-exec "$SCRIPT_PATH"/elixir --no-halt --erl "-user elixir" -e ":elixir.start_iex()" +iex "$@"
+exec "$SCRIPT_PATH"/elixir --no-halt --erl "-user elixir" +iex "$@"

bin/iex.bat

@@ -24,6 +24,6 @@ goto end
 
 :run
 if defined IEX_WITH_WERL (set __ELIXIR_IEX_FLAGS=--werl) else (set __ELIXIR_IEX_FLAGS=)
-call "%~dp0\elixir.bat" --no-halt --erl "-user elixir" -e ":elixir.start_iex()" +iex %__ELIXIR_IEX_FLAGS% %*
+call "%~dp0\elixir.bat" --no-halt --erl "-user elixir" +iex %__ELIXIR_IEX_FLAGS% %*
 :end
 endlocal

lib/eex/lib/eex/compiler.ex

@@ -71,11 +71,9 @@ defmodule EEx.Compiler do
       {:ok, expr, new_line, new_column, rest} ->
         {key, expr} =
           case :elixir_tokenizer.tokenize(expr, 1, file: "eex", check_terminators: false) do
-            {:ok, _line, _column, warnings, tokens} ->
-              Enum.each(Enum.reverse(warnings), fn {location, file, msg} ->
-                :elixir_errors.erl_warn(location, file, msg)
-              end)
-
+            {:ok, _line, _column, _warnings, tokens} ->
+              # We ignore warnings because the code will be tokenized
+              # again later with the right line+column info
               token_key(tokens, expr)
 
             {:error, _, _, _, _} ->

lib/eex/test/eex/tokenizer_test.exs

@@ -5,7 +5,7 @@ defmodule EEx.TokenizerTest do
 
   @opts [indentation: 0, trim: false]
 
-  test "simple chars lists" do
+  test "simple charlists" do
     assert EEx.tokenize(~c"foo", @opts) ==
              {:ok, [{:text, ~c"foo", %{column: 1, line: 1}}, {:eof, %{column: 4, line: 1}}]}
   end

lib/eex/test/eex_test.exs

@@ -463,17 +463,13 @@ defmodule EExTest do
       end
     end
 
-    test "when middle expression has a modifier" do
-      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
-               EEx.compile_string("foo <%= if true do %>true<%= else %>false<% end %>")
-             end) =~ ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= else %>\"]
-    end
+    test "when trying to use marker '|' without implementation" do
+      msg =
+        ~r/unsupported EEx syntax <%| %> \(the syntax is valid but not supported by the current EEx engine\)/
 
-    test "when end expression has a modifier" do
-      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
-               EEx.compile_string("foo <%= if true do %>true<% else %>false<%= end %>")
-             end) =~
-               ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= end %>\"]
+      assert_raise EEx.SyntaxError, msg, fn ->
+        EEx.compile_string("<%| true %>")
+      end
     end
 
     test "when trying to use marker '/' without implementation" do
@@ -485,17 +481,6 @@ defmodule EExTest do
       end
     end
 
-    test "when trying to use marker '|' without implementation" do
-      msg =
-        ~r/unsupported EEx syntax <%| %> \(the syntax is valid but not supported by the current EEx engine\)/
-
-      assert_raise EEx.SyntaxError, msg, fn ->
-        EEx.compile_string("<%| true %>")
-      end
-    end
-  end
-
-  describe "error messages" do
     test "honor line numbers" do
       assert_raise EEx.SyntaxError,
                    "nofile:100:6: expected closing '%>' for EEx expression",
@@ -516,18 +501,30 @@ defmodule EExTest do
         EEx.compile_string("foo <%= bar", file: "my_file.eex")
       end
     end
+  end
 
-    test "when <%!-- is not closed" do
-      message = """
-      my_file.eex:1:5: expected closing '--%>' for EEx expression
-        |
-      1 | foo <%!-- bar
-        |     ^\
-      """
+  describe "warnings" do
+    test "when middle expression has a modifier" do
+      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
+               EEx.compile_string("foo <%= if true do %>true<%= else %>false<% end %>")
+             end) =~ ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= else %>\"]
+    end
 
-      assert_raise EEx.SyntaxError, message, fn ->
-        EEx.compile_string("foo <%!-- bar", file: "my_file.eex")
-      end
+    test "when end expression has a modifier" do
+      assert ExUnit.CaptureIO.capture_io(:stderr, fn ->
+               EEx.compile_string("foo <%= if true do %>true<% else %>false<%= end %>")
+             end) =~
+               ~s[unexpected beginning of EEx tag \"<%=\" on \"<%= end %>\"]
+    end
+
+    test "from tokenizer" do
+      warning =
+        ExUnit.CaptureIO.capture_io(:stderr, fn ->
+          EEx.compile_string(~s'<%= :"foo" %>', file: "tokenizer.ex")
+        end)
+
+      assert warning =~ "found quoted atom \"foo\" but the quotes are not required"
+      assert warning =~ "tokenizer.ex:1:5"
     end
   end
 

lib/elixir/lib/access.ex

@@ -191,9 +191,13 @@ defmodule Access do
         case __STACKTRACE__ do
           [unquote(top) | _] ->
             reason =
-              "#{inspect(unquote(module))} does not implement the Access behaviour. " <>
-                "If you are using get_in/put_in/update_in, you can specify the field " <>
-                "to be accessed using Access.key!/1"
+              """
+              #{inspect(unquote(module))} does not implement the Access behaviour
+
+              You can use the "struct.field" syntax to access struct fields. \
+              You can also use Access.key!/1 to access struct fields dynamically \
+              inside get_in/put_in/update_in\
+              """
 
             %{unquote(exception) | reason: reason}
 
@@ -326,9 +330,23 @@ defmodule Access do
     end
   end
 
+  def get(list, key, _default) when is_list(list) and is_integer(key) do
+    raise ArgumentError, """
+    the Access module does not support accessing lists by index, got: #{inspect(key)}
+
+    Accessing a list by index is typically discouraged in Elixir, \
+    instead we prefer to use the Enum module to manipulate lists \
+    as a whole. If you really must access a list element by index, \
+    you can Enum.at/1 or the functions in the List module\
+    """
+  end
+
   def get(list, key, _default) when is_list(list) do
-    raise ArgumentError,
-          "the Access calls for keywords expect the key to be an atom, got: " <> inspect(key)
+    raise ArgumentError, """
+    the Access module supports only keyword lists (with atom keys), got: #{inspect(key)}
+
+    If you want to search lists of tuples, use List.keyfind/3\
+    """
   end
 
   def get(nil, _key, default) do
@@ -377,10 +395,26 @@ defmodule Access do
     Map.get_and_update(map, key, fun)
   end
 
-  def get_and_update(list, key, fun) when is_list(list) do
+  def get_and_update(list, key, fun) when is_list(list) and is_atom(key) do
     Keyword.get_and_update(list, key, fun)
   end
 
+  def get_and_update(list, key, _fun) when is_list(list) and is_integer(key) do
+    raise ArgumentError, """
+    the Access module does not support accessing lists by index, got: #{inspect(key)}
+
+    Accessing a list by index is typically discouraged in Elixir, \
+    instead we prefer to use the Enum module to manipulate lists \
+    as a whole. If you really must mostify a list element by index, \
+    you can Access.at/1 or the functions in the List module\
+    """
+  end
+
+  def get_and_update(list, key, _fun) when is_list(list) do
+    raise ArgumentError,
+          "the Access module supports only keyword lists (with atom keys), got: " <> inspect(key)
+  end
+
   def get_and_update(nil, key, _fun) do
     raise ArgumentError, "could not put/update key #{inspect(key)} on a nil value"
   end
@@ -507,6 +541,21 @@ defmodule Access do
       iex> get_in(map, [Access.key!(:user), Access.key!(:unknown)])
       ** (KeyError) key :unknown not found in: %{name: \"john\"}
 
+  The examples above could be partially written as:
+
+      iex> map = %{user: %{name: "john"}}
+      iex> map.user.name
+      "john"
+      iex> get_and_update_in(map.user.name, fn prev ->
+      ...>   {prev, String.upcase(prev)}
+      ...> end)
+      {"john", %{user: %{name: "JOHN"}}}
+
+  However, it is not possible to remove fields using the dot notation,
+  as it is implified those fields must also be present. In any case,
+  `Access.key!/1` is useful when the key is not known in advance
+  and must be accessed dynamically.
+
   An error is raised if the accessed structure is not a map/struct:
 
       iex> get_in([], [Access.key!(:foo)])

lib/elixir/lib/code.ex

@@ -1136,7 +1136,10 @@ defmodule Code do
     * syntax keywords (`fn`, `do`, `else`, and so on)
 
     * atoms containing interpolation (`:"#{1 + 1} is two"`), as these
-      atoms are constructed at runtime.
+      atoms are constructed at runtime
+
+    * atoms used to represent single-letter sigils like `:sigil_X`
+      (but multi-letter sigils like `:sigil_XYZ` are encoded).
 
   """
   @spec string_to_quoted(List.Chars.t(), keyword) ::

lib/elixir/lib/code/formatter.ex

@@ -431,7 +431,7 @@ defmodule Code.Formatter do
     {color("nil", nil, state.inspect_opts), state}
   end
 
-  defp quoted_to_algebra({:__block__, meta, _} = block, _context, state) do
+  defp quoted_to_algebra({:__block__, meta, args} = block, _context, state) when is_list(args) do
     {block, state} = block_to_algebra(block, line(meta), closing_line(meta), state)
     {surround("(", block, ")"), state}
   end
@@ -1419,7 +1419,9 @@ defmodule Code.Formatter do
 
   defp bitstring_segment_to_algebra({{:"::", _, [segment, spec]}, i}, state, last) do
     {doc, state} = quoted_to_algebra(segment, :parens_arg, state)
-    {spec, state} = bitstring_spec_to_algebra(spec, state, state.normalize_bitstring_modifiers)
+
+    {spec, state} =
+      bitstring_spec_to_algebra(spec, state, state.normalize_bitstring_modifiers, :"::")
 
     spec = wrap_in_parens_if_inspected_atom(spec)
     spec = if i == last, do: bitstring_wrap_parens(spec, i, last), else: spec
@@ -1438,15 +1440,17 @@ defmodule Code.Formatter do
     {bitstring_wrap_parens(doc, i, last), state}
   end
 
-  defp bitstring_spec_to_algebra({op, _, [left, right]}, state, normalize_modifiers)
+  defp bitstring_spec_to_algebra({op, _, [left, right]}, state, normalize_modifiers, paren_op)
        when op in [:-, :*] do
     normalize_modifiers = normalize_modifiers && op != :*
-    {left, state} = bitstring_spec_to_algebra(left, state, normalize_modifiers)
+    {left, state} = bitstring_spec_to_algebra(left, state, normalize_modifiers, op)
     {right, state} = bitstring_spec_element_to_algebra(right, state, normalize_modifiers)
-    {concat(concat(left, Atom.to_string(op)), right), state}
+    doc = concat(concat(left, Atom.to_string(op)), right)
+    doc = if paren_op == :*, do: wrap_in_parens(doc), else: doc
+    {doc, state}
   end
 
-  defp bitstring_spec_to_algebra(spec, state, normalize_modifiers) do
+  defp bitstring_spec_to_algebra(spec, state, normalize_modifiers, _paren_op) do
     bitstring_spec_element_to_algebra(spec, state, normalize_modifiers)
   end
 

lib/elixir/lib/code/fragment.ex

@@ -3,10 +3,6 @@ defmodule Code.Fragment do
   This module provides conveniences for analyzing fragments of
   textual code and extract available information whenever possible.
 
-  Most of the functions in this module provide a best-effort
-  and may not be accurate under all circumstances. Read each
-  documentation for more information.
-
   This module should be considered experimental.
   """
 
@@ -623,7 +619,7 @@ defmodule Code.Fragment do
     {reversed_pre, post} = adjust_position(reversed_pre, post)
 
     case take_identifier(post, []) do
-      {_, [], _} ->
+      :none ->
         maybe_operator(reversed_pre, post, line, opts)
 
       {:identifier, reversed_post, rest} ->
@@ -631,7 +627,7 @@ defmodule Code.Fragment do
         reversed = reversed_post ++ reversed_pre
 
         case codepoint_cursor_context(reversed, opts) do
-          {{:struct, acc}, offset} ->
+          {{:struct, acc}, offset} when acc != [] ->
             build_surround({:struct, acc}, reversed, line, offset)
 
           {{:alias, acc}, offset} ->
@@ -681,6 +677,9 @@ defmodule Code.Fragment do
           {{:alias, acc}, offset} ->
             build_surround({:alias, acc}, reversed, line, offset)
 
+          {{:alias, parent, acc}, offset} ->
+            build_surround({:alias, parent, acc}, reversed, line, offset)
+
           {{:struct, acc}, offset} ->
             build_surround({:struct, acc}, reversed, line, offset)
 
@@ -733,15 +732,31 @@ defmodule Code.Fragment do
     do: take_identifier(t, [h | acc])
 
   defp take_identifier(rest, acc) do
-    with {[?. | t], _} <- strip_spaces(rest, 0),
+    {stripped, _} = strip_spaces(rest, 0)
+
+    with [?. | t] <- stripped,
          {[h | _], _} when h in ?A..?Z <- strip_spaces(t, 0) do
       take_alias(rest, acc)
     else
-      _ -> {:identifier, acc, rest}
+      # Consider it an identifier if we are at the end of line
+      # or if we have spaces not followed by . (call) or / (arity)
+      _ when acc == [] and (rest == [] or (hd(rest) in @space and hd(stripped) not in ~c"/.")) ->
+        {:identifier, acc, rest}
+
+      # If we are immediately followed by a container, we are still part of the identifier.
+      # We don't consider << as it _may_ be an operator.
+      _ when acc == [] and hd(stripped) in ~c"({[" ->
+        {:identifier, acc, rest}
+
+      _ when acc == [] ->
+        :none
+
+      _ ->
+        {:identifier, acc, rest}
     end
   end
 
-  defp take_alias([h | t], acc) when h not in @non_identifier,
+  defp take_alias([h | t], acc) when h in ?A..?Z or h in ?a..?z or h in ?0..?9 or h == ?_,
     do: take_alias(t, [h | acc])
 
   defp take_alias(rest, acc) do

lib/elixir/lib/config/provider.ex

@@ -342,7 +342,7 @@ defmodule Config.Provider do
       * Make the runtime value match the compile time one
 
       * Recompile your project. If the misconfigured application is a dependency, \
-    you may need to run "mix deps.compile #{app} --force"
+    you may need to run "mix deps.clean #{app} --build"
 
       * Alternatively, you can disable this check. If you are using releases, you can \
     set :validate_compile_env to false in your release configuration. If you are \

lib/elixir/lib/enum.ex

@@ -3009,13 +3009,16 @@ defmodule Enum do
 
     if first < count and amount > 0 do
       amount = Kernel.min(amount, count - first)
-      amount = if step == 1, do: amount, else: div(amount - 1, step) + 1
+      amount = amount_with_step(amount, step)
       fun.(first, amount, step)
     else
       []
     end
   end
 
+  defp amount_with_step(amount, 1), do: amount
+  defp amount_with_step(amount, step), do: div(amount - 1, step) + 1
+
   @doc """
   Returns a subset list of the given `enumerable`, from `start_index` (zero-based)
   with `amount` number of elements if available.
@@ -4440,7 +4443,7 @@ defmodule Enum do
 
     if start >= 0 do
       amount = Kernel.min(amount, count - start)
-      amount = if step == 1, do: amount, else: div(amount - 1, step) + 1
+      amount = amount_with_step(amount, step)
       fun.(start, amount, step)
     else
       []
@@ -4448,7 +4451,7 @@ defmodule Enum do
   end
 
   defp slice_forward(list, start, amount, step) when is_list(list) do
-    amount = if step == 1, do: amount, else: div(amount - 1, step) + 1
+    amount = amount_with_step(amount, step)
     slice_list(list, start, amount, step)
   end
 
@@ -4458,7 +4461,7 @@ defmodule Enum do
         []
 
       {:ok, count, fun} when is_function(fun, 1) ->
-        amount = Kernel.min(amount, count - start)
+        amount = Kernel.min(amount, count - start) |> amount_with_step(step)
         enumerable |> fun.() |> slice_exact(start, amount, step, count)
 
       # TODO: Deprecate me in Elixir v1.18.
@@ -4473,8 +4476,7 @@ defmodule Enum do
         end
 
       {:ok, count, fun} when is_function(fun, 3) ->
-        amount = Kernel.min(amount, count - start)
-        amount = if step == 1, do: amount, else: div(amount - 1, step) + 1
+        amount = Kernel.min(amount, count - start) |> amount_with_step(step)
         fun.(start, amount, step)
 
       {:error, module} ->

lib/elixir/lib/float.ex

@@ -4,6 +4,9 @@ defmodule Float do
   @moduledoc """
   Functions for working with floating-point numbers.
 
+  For mathematical operations on top of floating-points,
+  see Erlang's [`:math`](`:math`) module.
+
   ## Kernel functions
 
   There are functions related to floating-point numbers on the `Kernel` module

lib/elixir/lib/io.ex

@@ -593,11 +593,11 @@ defmodule IO do
 
   Another example where you might want to collect a user input
   every new line and break on an empty line, followed by removing
-  redundant new line characters (`"\n"`):
+  redundant new line characters (`"\\n"`):
 
       IO.stream(:stdio, :line)
-      |> Enum.take_while(&(&1 != "\n"))
-      |> Enum.map(&String.replace(&1, "\n", ""))
+      |> Enum.take_while(&(&1 != "\\n"))
+      |> Enum.map(&String.replace(&1, "\\n", ""))
 
   """
   @spec stream(device, :line | pos_integer) :: Enumerable.t()

lib/elixir/lib/kernel.ex

@@ -3555,10 +3555,12 @@ defmodule Kernel do
       not bootstrapped?(Macro) ->
         nil
 
-      not function? and __CALLER__.context == :match ->
+      not function? and (__CALLER__.context == :match or __CALLER__.context == :guard) ->
         raise ArgumentError,
               """
-              invalid write attribute syntax. If you want to define an attribute, don't do this:
+              invalid usage of module attributes. Module attributes cannot be used inside \
+              pattern matching (and guards) outside of a function. If you are trying to \
+              define an attribute, do not do this:
 
                   @foo = :value
 
@@ -4901,17 +4903,6 @@ defmodule Kernel do
           {expanded, nil}
       end
 
-    # We do this so that the block is not tail-call optimized and stacktraces
-    # are not messed up. Basically, we just insert something between the return
-    # value of the block and what is returned by defmodule. Using just ":ok" or
-    # similar doesn't work because it's likely optimized away by the compiler.
-    block =
-      quote do
-        result = unquote(block)
-        :elixir_utils.noop()
-        result
-      end
-
     escaped =
       case env do
         %{function: nil, lexical_tracker: pid} when is_pid(pid) ->

lib/elixir/lib/port.ex

@@ -79,6 +79,27 @@ defmodule Port do
   are for advanced usage within the VM. Also consider using `System.cmd/3`
   if all you want is to execute a program and retrieve its return value.
 
+  > #### Windows argument splitting and untrusted arguments {: .warning}
+  >
+  > On Unix systems, arguments are passed to a new operating system
+  > process as an array of strings but on Windows it is up to the child
+  > process to parse them and some Windows programs may apply their own
+  > rules, which are inconsistent with the standard C runtime `argv` parsing
+  >
+  > This is particularly troublesome when invoking `.bat` or `.com` files
+  > as these run implicitly through `cmd.exe`, whose argument parsing is
+  > vulnerable to malicious input and can be used to run arbitrary shell
+  > commands.
+  >
+  > Therefore, if you are running on Windows and you execute batch
+  > files or `.com` applications, you must not pass untrusted input as
+  > arguments to the program. You may avoid accidentally executing them
+  > by explicitly passing the extension of the program you want to run,
+  > such as `.exe`, and double check the program is indeed not a batch
+  > file or `.com` application.
+  >
+  > This affects both `spawn` and `spawn_executable`.
+
   ### spawn
 
   The `:spawn` tuple receives a binary that is going to be executed as a

lib/elixir/lib/regex.ex

@@ -295,7 +295,7 @@ defmodule Regex do
   end
 
   @doc false
-  @deprecated "Use Kernel.is_struct/2 or pattern match on %Regex{} instead"
+  @deprecated "Use Kernel.is_struct(term, Regex) or pattern match on %Regex{} instead"
   def regex?(term)
   def regex?(%Regex{}), do: true
   def regex?(_), do: false

lib/elixir/lib/system.ex

@@ -996,6 +996,25 @@ defmodule System do
   `Port` module describes this problem and possible solutions under
   the "Zombie processes" section.
 
+  > #### Windows argument splitting and untrusted arguments {: .warning}
+  >
+  > On Unix systems, arguments are passed to a new operating system
+  > process as an array of strings but on Windows it is up to the child
+  > process to parse them and some Windows programs may apply their own
+  > rules, which are inconsistent with the standard C runtime `argv` parsing
+  >
+  > This is particularly troublesome when invoking `.bat` or `.com` files
+  > as these run implicitly through `cmd.exe`, whose argument parsing is
+  > vulnerable to malicious input and can be used to run arbitrary shell
+  > commands.
+  >
+  > Therefore, if you are running on Windows and you execute batch
+  > files or `.com` applications, you must not pass untrusted input as
+  > arguments to the program. You may avoid accidentally executing them
+  > by explicitly passing the extension of the program you want to run,
+  > such as `.exe`, and double check the program is indeed not a batch
+  > file or `.com` application.
+
   ## Examples
 
       iex> System.cmd("echo", ["hello"])

lib/elixir/lib/task/supervisor.ex

@@ -162,6 +162,7 @@ defmodule Task.Supervisor do
 
     * `:shutdown` - `:brutal_kill` if the tasks must be killed directly on shutdown
       or an integer indicating the timeout value, defaults to 5000 milliseconds.
+      The tasks must trap exits for the timeout to have an effect.
 
   """
   @spec async(Supervisor.supervisor(), (-> any), Keyword.t()) :: Task.t()
@@ -183,6 +184,7 @@ defmodule Task.Supervisor do
 
     * `:shutdown` - `:brutal_kill` if the tasks must be killed directly on shutdown
       or an integer indicating the timeout value, defaults to 5000 milliseconds.
+      The tasks must trap exits for the timeout to have an effect.
 
   """
   @spec async(Supervisor.supervisor(), module, atom, [term], Keyword.t()) :: Task.t()
@@ -208,6 +210,7 @@ defmodule Task.Supervisor do
 
     * `:shutdown` - `:brutal_kill` if the tasks must be killed directly on shutdown
       or an integer indicating the timeout value, defaults to 5000 milliseconds.
+      The tasks must trap exits for the timeout to have an effect.
 
   ## Compatibility with OTP behaviours
 
@@ -337,6 +340,7 @@ defmodule Task.Supervisor do
 
     * `:shutdown` - `:brutal_kill` if the tasks must be killed directly on shutdown
       or an integer indicating the timeout value. Defaults to `5000` milliseconds.
+      The tasks must trap exits for the timeout to have an effect.
 
   ## Examples
 
@@ -455,6 +459,7 @@ defmodule Task.Supervisor do
 
     * `:shutdown` - `:brutal_kill` if the task must be killed directly on shutdown
       or an integer indicating the timeout value, defaults to 5000 milliseconds.
+      The task must trap exits for the timeout to have an effect.
 
   """
   @spec start_child(Supervisor.supervisor(), (-> any), keyword) ::

lib/elixir/lib/uri.ex

@@ -648,16 +648,16 @@ defmodule URI do
         scheme = String.downcase(scheme, :ascii)
 
         case map do
-          %{port: port} when port != :undefined ->
+          %{port: port} when is_integer(port) ->
             %{uri | scheme: scheme}
 
           %{} ->
-            case default_port(scheme) do
-              nil -> %{uri | scheme: scheme}
-              port -> %{uri | scheme: scheme, port: port}
-            end
+            %{uri | scheme: scheme, port: default_port(scheme)}
         end
 
+      %{port: :undefined} ->
+        %{uri | port: nil}
+
       %{} ->
         uri
     end

lib/elixir/pages/compatibility-and-deprecations.md

@@ -8,12 +8,11 @@ Elixir applies bug fixes only to the latest minor branch. Security patches are a
 
 Elixir version | Support
 :------------- | :-----------------------------
-1.15           | Development
-1.14           | Bug fixes and security patches
+1.15           | Bug fixes and security patches
+1.14           | Security patches only
 1.13           | Security patches only
 1.12           | Security patches only
 1.11           | Security patches only
-1.10           | Security patches only
 
 New releases are announced in the read-only [announcements mailing list](https://groups.google.com/group/elixir-lang-ann). All security releases [will be tagged with `[security]`](https://groups.google.com/forum/#!searchin/elixir-lang-ann/%5Bsecurity%5D%7Csort:date).
 
@@ -44,7 +43,7 @@ Erlang/OTP versioning is independent from the versioning of Elixir. Erlang relea
 Elixir version | Supported Erlang/OTP versions
 :------------- | :-------------------------------
 1.15           | 24 - 26
-1.14           | 23 - 25
+1.14           | 23 - 25 (and Erlang/OTP 26 from v1.14.5)
 1.13           | 22 - 24 (and Erlang/OTP 25 from v1.13.4)
 1.12           | 22 - 24
 1.11           | 21 - 23 (and Erlang/OTP 24 from v1.11.4)
@@ -82,7 +81,7 @@ Version | Deprecated feature                                  | Replaced by (ava
 :-------| :-------------------------------------------------- | :---------------------------------------------------------------
 [v1.15] | `Calendar.ISO.day_of_week/3`                        | `Calendar.ISO.day_of_week/4` (v1.11)
 [v1.15] | `Exception.exception?/1`                            | `Kernel.is_exception/1` (v1.11)
-[v1.15] | `Regex.regex?/1`                                    | `Kernel.is_struct/2` (v1.11)
+[v1.15] | `Regex.regex?/1`                                    | `Kernel.is_struct/2` (`Kernel.is_struct(term, Regex)`) (v1.11)
 [v1.15] | `Logger.warn/2`                                     | `Logger.warning/2` (v1.11)
 [v1.14] | `use Bitwise`                                       | `import Bitwise` (v1.0)
 [v1.14] | `~~~/1`                                             | `bnot/2` (v1.0)

lib/elixir/scripts/windows_installer/.gitignore

@@ -0,0 +1 @@
+tmp/

lib/elixir/scripts/windows_installer/build.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+# Usage:
+#
+# With Elixir archive:
+#
+#     ELIXIR_ZIP=Precompiled.zip OTP_VERSION=25.3.2.2 ./build.sh
+#
+# With Elixir version:
+#
+#     ELIXIR_VERSION=1.14.5 OTP_VERSION=25.3.2.2 ./build.sh
+set -euo pipefail
+
+OTP_VERSION="${OTP_VERSION:-26.0}"
+otp_release=`echo "${OTP_VERSION}" | cut -d. -f1`
+
+mkdir -p tmp
+
+ELIXIR_VERSION="${ELIXIR_VERSION:-}"
+if [ -n "${ELIXIR_VERSION}" ]; then
+  ELIXIR_ZIP="tmp/elixir-${ELIXIR_VERSION}-otp-${otp_release}.zip"
+  if [ ! -f "${ELIXIR_ZIP}" ]; then
+    url="https://github.com/elixir-lang/elixir/releases/download/v${ELIXIR_VERSION}/elixir-otp-${otp_release}.zip"
+    echo "downloading ${url}"
+    curl --fail -L -o "${ELIXIR_ZIP}" "${url}"
+  fi
+  basename=elixir-${ELIXIR_VERSION}-otp-${otp_release}
+else
+  basename=elixir-otp-${otp_release}
+fi
+
+if [ ! -d "tmp/${basename}" ]; then
+  unzip -d "tmp/${basename}" "${ELIXIR_ZIP}"
+fi
+
+# brew install makensis
+# apt install -y nsis
+# choco install -y nsis
+export PATH="/c/Program Files (x86)/NSIS:${PATH}"
+makensis \
+  -X"OutFile tmp\\${basename}.exe" \
+  -DOTP_VERSION=${OTP_VERSION} \
+  -DOTP_RELEASE="${otp_release}" \
+  -DELIXIR_DIR=tmp\\${basename} \
+  installer.nsi
+
+echo "Installer path: tmp/${basename}.exe"

lib/elixir/scripts/windows_installer/installer.nsi

@@ -0,0 +1,275 @@
+!include "MUI2.nsh"
+!include "StrFunc.nsh"
+${Using:StrFunc} UnStrStr
+
+Name "Elixir"
+ManifestDPIAware true
+Unicode True
+InstallDir "$PROGRAMFILES64\Elixir"
+!define MUI_ICON "assets\drop.ico"
+
+; Install Page: Install Erlang/OTP
+
+Page custom CheckOTPPageShow CheckOTPPageLeave
+
+var InstalledOTPRelease
+var OTPPath
+
+var Dialog
+var NoOTPLabel
+var NoOTPLabelCreated
+var OTPMismatchLabel
+var OTPMismatchLabelCreated
+var DownloadOTPLink
+var DownloadOTPLinkCreated
+var VerifyOTPButton
+var VerifyOTPButtonCreated
+Function CheckOTPPageShow
+  !insertmacro MUI_HEADER_TEXT "Checking Erlang/OTP" ""
+
+  nsDialogs::Create 1018
+  Pop $Dialog
+
+  ${If} $Dialog == error
+    Abort
+  ${EndIf}
+
+  Call VerifyOTP
+
+  nsDialogs::Show
+FunctionEnd
+
+Function VerifyOTP
+  ${If} $NoOTPLabelCreated == "true"
+    ShowWindow $NoOTPLabel ${SW_HIDE}
+  ${EndIf}
+
+  ${If} $OTPMismatchLabelCreated == "true"
+    ShowWindow $OTPMismatchLabel ${SW_HIDE}
+  ${EndIf}
+
+  ${If} $DownloadOTPLinkCreated == "true"
+    ShowWindow $DownloadOTPLink ${SW_HIDE}
+  ${Else}
+    StrCpy $DownloadOTPLinkCreated "true"
+    ${NSD_CreateLink}  0 60u 100% 20u "Download Erlang/OTP ${OTP_RELEASE}"
+    Pop $DownloadOTPLink
+    ${NSD_OnClick} $DownloadOTPLink OpenOTPDownloads
+    ShowWindow $DownloadOTPLink ${SW_HIDE}
+  ${EndIf}
+
+  ${If} $VerifyOTPButtonCreated == "true"
+    ShowWindow $VerifyOTPButton ${SW_HIDE}
+  ${Else}
+    StrCpy $VerifyOTPButtonCreated "true"
+    ${NSD_CreateButton} 0 80u 25% 12u "Verify Erlang/OTP"
+    Pop $VerifyOTPButton
+    ${NSD_OnClick} $VerifyOTPButton VerifyOTP
+    ShowWindow $VerifyOTPButton ${SW_HIDE}
+  ${EndIf}
+
+  StrCpy $0 0
+  loop:
+    EnumRegKey $1 HKLM "SOFTWARE\WOW6432NODE\Ericsson\Erlang" $0
+    StrCmp $1 "" done
+    ReadRegStr $1 HKLM "SOFTWARE\WOW6432NODE\Ericsson\Erlang\$1" ""
+    StrCpy $OTPPath $1
+    IntOp $0 $0 + 1
+    goto loop
+  done:
+
+  ${If} $OTPPath == ""
+    ${If} $NoOTPLabelCreated != "true"
+      StrCpy $NoOTPLabelCreated "true"
+      ${NSD_CreateLabel} 0 0   100% 20u "Couldn't find existing Erlang/OTP installation. Click the link below to download and install it before proceeding."
+      Pop $NoOTPLabel
+    ${EndIf}
+
+    ShowWindow $NoOTPLabel ${SW_SHOW}
+    ShowWindow $DownloadOTPLink ${SW_SHOW}
+    ShowWindow $VerifyOTPButton ${SW_SHOW}
+
+  ${Else}
+    nsExec::ExecToStack `$OTPPath\bin\erl.exe -noinput -eval "\
+    io:put_chars(erlang:system_info(otp_release)),\
+    halt()."`
+    Pop $0
+    Pop $1
+
+    ${If} $0 == 0
+      StrCpy $InstalledOTPRelease $1
+      ${If} $InstalledOTPRelease == ${OTP_RELEASE}
+        ${NSD_CreateLabel} 0 0 100% 60u "Found existing Erlang/OTP $InstalledOTPRelease installation at $OTPPath. Please proceed."
+
+      ${Else}
+        ${If} $OTPMismatchLabelCreated != "true"
+          StrCpy $OTPMismatchLabelCreated "true"
+          ${NSD_CreateLabel} 0 0 100% 60u "Found existing Erlang/OTP $InstalledOTPRelease installation at $OTPPath but this Elixir installer was precompiled for Erlang/OTP ${OTP_RELEASE}. \
+          $\r$\n$\r$\nYou can either search for another Elixir installer precompiled for Erlang/OTP $InstalledOTPRelease or download Erlang/OTP ${OTP_RELEASE} and install before proceeding."
+          Pop $OTPMismatchLabel
+        ${EndIf}
+
+        ShowWindow $OTPMismatchLabel ${SW_SHOW}
+        ShowWindow $DownloadOTPLink  ${SW_SHOW}
+        ShowWindow $VerifyOTPButton  ${SW_SHOW}
+      ${EndIf}
+    ${Else}
+      SetErrorlevel 5
+      MessageBox MB_ICONSTOP "Found existing Erlang/OTP installation at $OTPPath but checking it exited with $0: $1"
+    ${EndIf}
+  ${EndIf}
+FunctionEnd
+
+Function OpenOTPDownloads
+  ExecShell "open" "https://www.erlang.org/downloads/${OTP_RELEASE}"
+FunctionEnd
+
+Function CheckOTPPageLeave
+FunctionEnd
+
+; Install Page: Files
+
+!insertmacro MUI_PAGE_DIRECTORY
+!insertmacro MUI_PAGE_INSTFILES
+
+; Install Page: Finish
+
+Page custom FinishPageShow FinishPageLeave
+
+var AddOTPToPathCheckbox
+var AddElixirToPathCheckbox
+Function FinishPageShow
+  !insertmacro MUI_HEADER_TEXT "Finish Setup" ""
+
+  nsDialogs::Create 1018
+  Pop $Dialog
+
+  ${If} $Dialog == error
+    Abort
+  ${EndIf}
+
+  ; we add to PATH using erlang, so there must be an OTP installed to do so.
+  ${If} "$OTPPath" != ""
+    ${NSD_CreateCheckbox} 0 0 195u 10u "&Add $INSTDIR\bin to %PATH%"
+    Pop $AddElixirToPathCheckbox
+    SendMessage $AddElixirToPathCheckbox ${BM_SETCHECK} ${BST_CHECKED} 0
+
+    ${NSD_CreateCheckbox} 0 20u 195u 10u "&Add $OTPPath\bin to %PATH%"
+    Pop $AddOTPToPathCheckbox
+    SendMessage $AddOTPToPathCheckbox ${BM_SETCHECK} ${BST_CHECKED} 0
+
+    ${NSD_CreateLabel} 0 40u 100% 20u "Note: you need to restart your shell for the environment variable changes to take effect."
+  ${EndIf}
+
+  nsDialogs::Show
+FunctionEnd
+
+var PathsToAdd
+Function FinishPageLeave
+  ${NSD_GetState} $AddOTPToPathCheckbox $0
+  ${If} $0 <> ${BST_UNCHECKED}
+    StrCpy $PathsToAdd ";$OTPPath\bin"
+  ${EndIf}
+
+  ${NSD_GetState} $AddElixirToPathCheckbox $0
+  ${If} $0 <> ${BST_UNCHECKED}
+    StrCpy $PathsToAdd "$PathsToAdd;$INSTDIR\bin"
+  ${EndIf}
+
+  ${If} "$PathsToAdd" != ""
+    nsExec::ExecToStack `"$OTPPath\bin\escript.exe" "$INSTDIR\update_system_path.erl" add "$PathsToAdd"`
+    Pop $0
+    Pop $1
+    ${If} $0 != 0
+      SetErrorlevel 5
+      MessageBox MB_ICONSTOP "adding paths failed with $0: $1"
+      Quit
+    ${EndIf}
+  ${EndIf}
+FunctionEnd
+
+Section "Install Elixir" SectionElixir
+  SetOutPath "$INSTDIR"
+  File /r "${ELIXIR_DIR}\"
+  File "update_system_path.erl"
+
+  WriteUninstaller "Uninstall.exe"
+SectionEnd
+
+; Uninstall Page: Remove from %PATH%
+
+var RemoveOTPFromPathCheckbox
+var RemoveElixirFromPathCheckbox
+Function un.FinishPageShow
+  !insertmacro MUI_HEADER_TEXT "Remove from %PATH%" ""
+
+  StrCpy $0 0
+  loop:
+    EnumRegKey $1 HKLM "SOFTWARE\WOW6432NODE\Ericsson\Erlang" $0
+    StrCmp $1 "" done
+    ReadRegStr $1 HKLM "SOFTWARE\WOW6432NODE\Ericsson\Erlang\$1" ""
+    StrCpy $OTPPath $1
+    IntOp $0 $0 + 1
+    goto loop
+  done:
+
+  nsDialogs::Create 1018
+  Pop $Dialog
+
+  ${If} $Dialog == error
+    Abort
+  ${EndIf}
+
+  ReadRegStr $0 HKCU "Environment" "Path"
+
+  ${UnStrStr} $1 "$0" "$INSTDIR\bin"
+  ${If} $1 != ""
+    ${NSD_CreateCheckbox} 0 0 195u 10u "&Remove $INSTDIR\bin from %PATH%"
+    Pop $RemoveElixirFromPathCheckbox
+    SendMessage $RemoveElixirFromPathCheckbox ${BM_SETCHECK} ${BST_CHECKED} 0
+  ${EndIf}
+
+  ${UnStrStr} $1 "$0" "$OTPPath\bin"
+  ${If} $1 != ""
+    ${NSD_CreateCheckbox} 0 20u 195u 10u "&Remove $OTPPath\bin from %PATH%"
+    Pop $RemoveOTPFromPathCheckbox
+    SendMessage $RemoveOTPFromPathCheckbox ${BM_SETCHECK} ${BST_CHECKED} 0
+  ${EndIf}
+
+  nsDialogs::Show
+FunctionEnd
+
+var PathsToRemove
+Function un.FinishPageLeave
+  ${NSD_GetState} $RemoveOTPFromPathCheckbox $1
+  ${If} $1 <> ${BST_UNCHECKED}
+    StrCpy $PathsToRemove ";$OTPPath\bin"
+  ${EndIf}
+
+  ${NSD_GetState} $RemoveElixirFromPathCheckbox $1
+  ${If} $1 <> ${BST_UNCHECKED}
+    StrCpy $PathsToRemove "$PathsToRemove;$INSTDIR\bin"
+  ${EndIf}
+
+  ${If} "$PathsToRemove" != ""
+    nsExec::ExecToStack `"$OTPPath\bin\escript.exe" "$INSTDIR\update_system_path.erl" remove "$PathsToRemove"`
+    Pop $0
+    Pop $1
+    ${If} $0 != 0
+      SetErrorlevel 5
+      MessageBox MB_ICONSTOP "removing paths failed with $0: $1"
+      Quit
+    ${EndIf}
+  ${EndIf}
+FunctionEnd
+
+UninstPage custom un.FinishPageShow un.FinishPageLeave
+
+!insertmacro MUI_UNPAGE_DIRECTORY
+!insertmacro MUI_UNPAGE_INSTFILES
+
+Section "Uninstall"
+  RMDir /r "$INSTDIR"
+SectionEnd
+
+!insertmacro MUI_LANGUAGE "English"

lib/elixir/scripts/windows_installer/update_system_path.erl

@@ -0,0 +1,42 @@
+#!/usr/bin/env escript
+%%! -noinput
+
+%% This file is used by the Elixir installer and uninstaller.
+main(["add", ";" ++ PathsToAdd]) ->
+  {ok, Reg} = win32reg:open([read, write]),
+  ok = win32reg:change_key(Reg, "\\hkey_current_user\\environment"),
+  {ok, SystemPath} = win32reg:value(Reg, "path"),
+
+  NewSystemPath =
+    lists:foldl(
+      fun(Elem, Acc) ->
+        Elem ++ ";" ++
+          binary_to_list(
+            iolist_to_binary(
+              string:replace(Acc, Elem ++ ";", "", all)))
+      end,
+      SystemPath,
+      string:split(PathsToAdd, ";", all)
+    ),
+
+  ok = win32reg:set_value(Reg, "Path", NewSystemPath),
+  ok;
+
+main(["remove", ";" ++ PathsToRemove]) ->
+  {ok, Reg} = win32reg:open([read, write]),
+  ok = win32reg:change_key(Reg, "\\hkey_current_user\\environment"),
+  {ok, SystemPath} = win32reg:value(Reg, "path"),
+
+  NewSystemPath =
+    lists:foldl(
+      fun(Elem, Acc) ->
+        binary_to_list(
+          iolist_to_binary(
+            string:replace(Acc, Elem ++ ";", "", all)))
+      end,
+      SystemPath,
+      string:split(PathsToRemove, ";", all)
+    ),
+
+  ok = win32reg:set_value(Reg, "Path", NewSystemPath),
+  ok.

lib/elixir/src/elixir.erl

@@ -7,10 +7,11 @@
 -export([
   string_to_tokens/5, tokens_to_quoted/3, 'string_to_quoted!'/5,
   env_for_eval/1, quoted_to_erl/2, eval_forms/3, eval_quoted/3,
-  eval_quoted/4
+  eval_quoted/4, eval_external_handler/3
 ]).
 -include("elixir.hrl").
 -define(system, 'Elixir.System').
+-define(elixir_eval_env, {elixir, eval_env}).
 
 %% Top level types
 %% TODO: Remove char_list type on v2.0
@@ -192,7 +193,8 @@ start_cli() ->
   'Elixir.Kernel.CLI':main(init:get_plain_arguments()),
   elixir_config:booted().
 
-%% TODO: Delete prim_tty branches and -user on Erlang/OTP 26.
+%% TODO: Delete prim_tty branches and -user on Erlang/OTP 26
+%% and add "-e :elixir.start_iex" to bin/iex instead of $MODE.
 start() ->
   case code:ensure_loaded(prim_tty) of
     {module, _} ->
@@ -207,6 +209,7 @@ start() ->
 start_iex() ->
   case code:ensure_loaded(prim_tty) of
     {module, _} ->
+      start_cli(),
       spawn(fun() ->
         elixir_config:wait_until_booted(),
         (shell:whereis() =:= undefined) andalso 'Elixir.IEx':cli()
@@ -355,8 +358,25 @@ eval_forms(Tree, Binding, OrigE, Opts) ->
           _ -> [Erl]
         end,
 
-      ExternalHandler = eval_external_handler(NewE),
-      {value, Value, NewBinding} = erl_eval:exprs(Exprs, ErlBinding, none, ExternalHandler),
+      ExternalHandler = eval_external_handler(),
+
+      {value, Value, NewBinding} =
+        try
+          %% ?elixir_eval_env is used by the external handler.
+          %%
+          %% The reason why we use the process dictionary to pass the environment
+          %% is because we want to avoid passing closures to erl_eval, as that
+          %% would effectively tie the eval code to the Elixir version and it is
+          %% best if it depends solely on Erlang/OTP.
+          %%
+          %% The downside is that functions that escape the eval context will no
+          %% longer have the original environment they came from.
+          erlang:put(?elixir_eval_env, NewE),
+          erl_eval:exprs(Exprs, ErlBinding, none, ExternalHandler)
+        after
+          erlang:erase(?elixir_eval_env)
+        end,
+
       PruneBefore = if Prune -> length(Binding); true -> -1 end,
 
       {DumpedBinding, DumpedVars} =
@@ -367,52 +387,60 @@ eval_forms(Tree, Binding, OrigE, Opts) ->
 
 %% TODO: Remove conditional once we require Erlang/OTP 25+.
 -if(?OTP_RELEASE >= 25).
-eval_external_handler(Env) ->
-  Fun = fun(Ann, FunOrModFun, Args) ->
-    try
-      case FunOrModFun of
-        {Mod, Fun} -> apply(Mod, Fun, Args);
-        Fun -> apply(Fun, Args)
-      end
-    catch
-      Kind:Reason:Stacktrace ->
-        %% Take everything up to the Elixir module
-        Pruned =
-          lists:takewhile(fun
-            ({elixir,_,_,_}) -> false;
-            (_) -> true
-          end, Stacktrace),
+eval_external_handler() ->
+  {value, fun ?MODULE:eval_external_handler/3}.
 
-        Caller =
-          lists:dropwhile(fun
-            ({elixir,_,_,_}) -> false;
-            (_) -> true
-          end, Stacktrace),
-
-        %% Now we prune any shared code path from erl_eval
-        {current_stacktrace, Current} =
-          erlang:process_info(self(), current_stacktrace),
-
-        %% We need to make sure that we don't generate more
-        %% frames than supported. So we do our best to drop
-        %% from the Caller, but if the caller has no frames,
-        %% we need to drop from Pruned.
-        {DroppedCaller, ToDrop} =
-          case Caller of
-            [] -> {[], true};
-            _ -> {lists:droplast(Caller), false}
-          end,
-
-        Reversed = drop_common(lists:reverse(Current), lists:reverse(Pruned), ToDrop),
-        File = elixir_utils:characters_to_list(?key(Env, file)),
-        Location = [{file, File}, {line, erl_anno:line(Ann)}],
-
-        %% Add file+line information at the bottom
-        Custom = lists:reverse([{elixir_eval, '__FILE__', 1, Location} | Reversed], DroppedCaller),
-        erlang:raise(Kind, Reason, Custom)
+eval_external_handler(Ann, FunOrModFun, Args) ->
+  try
+    case FunOrModFun of
+      {Mod, Fun} -> apply(Mod, Fun, Args);
+      Fun -> apply(Fun, Args)
     end
-  end,
-  {value, Fun}.
+  catch
+    Kind:Reason:Stacktrace ->
+      %% Take everything up to the Elixir module
+      Pruned =
+        lists:takewhile(fun
+          ({elixir,_,_,_}) -> false;
+          (_) -> true
+        end, Stacktrace),
+
+      Caller =
+        lists:dropwhile(fun
+          ({elixir,_,_,_}) -> false;
+          (_) -> true
+        end, Stacktrace),
+
+      %% Now we prune any shared code path from erl_eval
+      {current_stacktrace, Current} =
+        erlang:process_info(self(), current_stacktrace),
+
+      %% We need to make sure that we don't generate more
+      %% frames than supported. So we do our best to drop
+      %% from the Caller, but if the caller has no frames,
+      %% we need to drop from Pruned.
+      {DroppedCaller, ToDrop} =
+        case Caller of
+          [] -> {[], true};
+          _ -> {lists:droplast(Caller), false}
+        end,
+
+      Reversed = drop_common(lists:reverse(Current), lists:reverse(Pruned), ToDrop),
+
+      %% Add file+line information at the bottom
+      Bottom =
+        case erlang:get(?elixir_eval_env) of
+          #{file := File} ->
+            [{elixir_eval, '__FILE__', 1,
+             [{file, elixir_utils:characters_to_list(File)}, {line, erl_anno:line(Ann)}]}];
+
+          _ ->
+            []
+        end,
+
+      Custom = lists:reverse(Bottom ++ Reversed, DroppedCaller),
+      erlang:raise(Kind, Reason, Custom)
+  end.
 
 %% We need to check if we have dropped any frames.
 %% If we have not dropped frames, then we need to drop one
@@ -425,8 +453,8 @@ drop_common([], [{?MODULE, _, _, _} | T2], _ToDrop) -> T2;
 drop_common([], [_ | T2], true) -> T2;
 drop_common([], T2, _) -> T2.
 -else.
-eval_external_handler(_Env) ->
-  none.
+eval_external_handler() -> none.
+eval_external_handler(_Ann, _FunOrModFun, _Args) -> error(unused).
 -endif.
 
 %% Converts a quoted expression to Erlang abstract format

lib/elixir/src/elixir_compiler.erl

@@ -16,7 +16,7 @@ quoted(Forms, File, Callback) ->
 
     elixir_lexical:run(
       Env,
-      fun (LexicalEnv) -> eval_or_compile(Forms, [], LexicalEnv) end,
+      fun (LexicalEnv) -> maybe_fast_compile(Forms, [], LexicalEnv) end,
       fun (#{lexical_tracker := Pid}) -> Callback(File, Pid) end
     ),
 
@@ -32,7 +32,7 @@ file(File, Callback) ->
 %% Evaluates the given code through the Erlang compiler.
 %% It may end-up evaluating the code if it is deemed a
 %% more efficient strategy depending on the code snippet.
-eval_or_compile(Forms, Args, E) ->
+maybe_fast_compile(Forms, Args, E) ->
   case (?key(E, module) == nil) andalso allows_fast_compilation(Forms) andalso
         (not elixir_config:is_bootstrap()) of
     true  -> fast_compile(Forms, E);
@@ -40,8 +40,9 @@ eval_or_compile(Forms, Args, E) ->
   end,
   ok.
 
-compile(Quoted, ArgsList, E) ->
-  {Expanded, SE, EE} = elixir_expand:expand(Quoted, elixir_env:env_to_ex(E), E),
+compile(Quoted, ArgsList, #{line := Line} = E) ->
+  Block = no_tail_optimize([{line, Line}], Quoted),
+  {Expanded, SE, EE} = elixir_expand:expand(Block, elixir_env:env_to_ex(E), E),
   elixir_env:check_unused_vars(SE, EE),
 
   {Module, Fun, Purgeable} =
@@ -55,7 +56,7 @@ spawned_compile(ExExprs, #{line := Line, file := File} = E) ->
   {ErlExprs, _} = elixir_erl_pass:translate(ExExprs, erl_anno:new(Line), S),
 
   Module = retrieve_compiler_module(),
-  Fun  = code_fun(?key(E, module)),
+  Fun = code_fun(?key(E, module)),
   Forms = code_mod(Fun, ErlExprs, Line, File, Module, Vars),
 
   {Module, Binary} = elixir_erl_compiler:noenv_forms(Forms, File, [nowarn_nomatch, no_bool_opt, no_ssa_opt]),
@@ -106,15 +107,9 @@ allows_fast_compilation(_) ->
 
 fast_compile({'__block__', _, Exprs}, E) ->
   lists:foldl(fun(Expr, _) -> fast_compile(Expr, E) end, nil, Exprs);
-fast_compile({defmodule, Meta, [Mod, [{do, TailBlock}]]}, NoLineE) ->
+fast_compile({defmodule, Meta, [Mod, [{do, Block}]]}, NoLineE) ->
   E = NoLineE#{line := ?line(Meta)},
 
-  Block = {'__block__', Meta, [
-    {'=', Meta, [{result, Meta, ?MODULE}, TailBlock]},
-    {{'.', Meta, [elixir_utils, noop]}, Meta, []},
-    {result, Meta, ?MODULE}
-  ]},
-
   Expanded = case Mod of
     {'__aliases__', _, _} ->
       case elixir_aliases:expand_or_concat(Mod, E) of
@@ -129,6 +124,13 @@ fast_compile({defmodule, Meta, [Mod, [{do, TailBlock}]]}, NoLineE) ->
   ContextModules = [Expanded | ?key(E, context_modules)],
   elixir_module:compile(Expanded, Block, [], false, E#{context_modules := ContextModules}).
 
+no_tail_optimize(Meta, Block) ->
+  {'__block__', Meta, [
+    {'=', Meta, [{result, Meta, ?MODULE}, Block]},
+    {{'.', Meta, [elixir_utils, noop]}, Meta, []},
+    {result, Meta, ?MODULE}
+  ]}.
+
 %% Bootstrapper
 
 bootstrap() ->

lib/elixir/src/elixir_dispatch.erl

@@ -130,11 +130,15 @@ dispatch_require(Meta, Receiver, Name, Args, S, E, Callback) when is_atom(Receiv
 
   case elixir_rewrite:inline(Receiver, Name, Arity) of
     {AR, AN} ->
+      elixir_env:trace({remote_function, Meta, Receiver, Name, Arity}, E),
       Callback(AR, AN, Args);
     false ->
       case expand_require(Meta, Receiver, {Name, Arity}, Args, S, E) of
-        {ok, Receiver, Quoted} -> expand_quoted(Meta, Receiver, Name, Arity, Quoted, S, E);
-        error -> Callback(Receiver, Name, Args)
+        {ok, Receiver, Quoted} ->
+          expand_quoted(Meta, Receiver, Name, Arity, Quoted, S, E);
+        error ->
+          elixir_env:trace({remote_function, Meta, Receiver, Name, Arity}, E),
+          Callback(Receiver, Name, Args)
       end
   end;
 

lib/elixir/src/elixir_erl.erl

@@ -510,12 +510,15 @@ get_moduledoc_meta(Set) ->
 
 get_docs(Set, Module, Definitions, Kind) ->
   [{Key,
-    erl_anno:new(Line),
+    maybe_generated(erl_anno:new(Line), Ctx),
     [signature_to_binary(Module, Name, Signature)],
     doc_value(Doc, Name),
     Meta
    } || {Name, Arity} <- Definitions,
-        {Key, _Ctx, Line, Signature, Doc, Meta} <- ets:lookup(Set, {Kind, Name, Arity})].
+        {Key, Ctx, Line, Signature, Doc, Meta} <- ets:lookup(Set, {Kind, Name, Arity})].
+
+maybe_generated(Ann, nil) -> Ann;
+maybe_generated(Ann, _Ctx) -> erl_anno:set_generated(true, Ann).
 
 get_callback_docs(Set, Callbacks) ->
   [{Key,

lib/elixir/src/elixir_erl_compiler.erl

@@ -5,25 +5,42 @@
 spawn(Fun) ->
   CompilerInfo = get(elixir_compiler_info),
 
+  CodeDiagnostics =
+    case get(elixir_code_diagnostics) of
+      undefined -> undefined;
+      {_Tail, Log} -> {[], Log}
+    end,
+
   {_, Ref} =
     spawn_monitor(fun() ->
       put(elixir_compiler_info, CompilerInfo),
+      put(elixir_code_diagnostics, CodeDiagnostics),
 
       try Fun() of
-        Result -> exit({ok, Result})
+        Result -> exit({ok, Result, get(elixir_code_diagnostics)})
       catch
         Kind:Reason:Stack ->
-          exit({Kind, Reason, Stack})
+          exit({Kind, Reason, Stack, get(elixir_code_diagnostics)})
       end
     end),
 
   receive
-    {'DOWN', Ref, process, _, {ok, Result}} ->
+    {'DOWN', Ref, process, _, {ok, Result, Diagnostics}} ->
+      copy_diagnostics(Diagnostics),
       Result;
-    {'DOWN', Ref, process, _, {Kind, Reason, Stack}} ->
+    {'DOWN', Ref, process, _, {Kind, Reason, Stack, Diagnostics}} ->
+      copy_diagnostics(Diagnostics),
       erlang:raise(Kind, Reason, Stack)
   end.
 
+copy_diagnostics(undefined) ->
+  ok;
+copy_diagnostics({Head, _}) ->
+  case get(elixir_code_diagnostics) of
+    undefined -> ok;
+    {Tail, Log} -> put(elixir_code_diagnostics, {Head ++ Tail, Log})
+  end.
+
 forms(Forms, File, Opts) ->
   compile(Forms, File, Opts ++ compile:env_compiler_options()).
 

lib/elixir/src/elixir_erl_try.erl

@@ -55,7 +55,7 @@ normalize_rescue(Meta, Var, Pattern, Expr, ErlangAliases) ->
         dynamic_normalize(Meta, Var, ?REQUIRES_STACKTRACE);
 
       false ->
-        case lists:splitwith(fun is_normalized_with_stacktrace/1, ErlangAliases) of
+        case lists:partition(fun is_normalized_with_stacktrace/1, ErlangAliases) of
           {[], _} -> [];
           {_, []} -> {'__STACKTRACE__', Meta, nil};
           {Some, _} -> dynamic_normalize(Meta, Var, Some)

lib/elixir/src/elixir_errors.erl

@@ -170,13 +170,22 @@ parse_error(Location, File, <<"syntax error before: ">>, Keyword, Input)
 
 %% Produce a human-readable message for errors before a sigil
 parse_error(Location, File, <<"syntax error before: ">>, <<"{sigil,", _Rest/binary>> = Full, Input) ->
-  {sigil, _, Sigil, [Content | _], _, _, _} = parse_erl_term(Full),
+  {sigil, _, Atom, [Content | _], _, _, _} = parse_erl_term(Full),
   Content2 = case is_binary(Content) of
     true -> Content;
     false -> <<>>
   end,
-  SigilName = list_to_binary(Sigil),
-  Message = <<"syntax error before: sigil \~", SigilName/binary, " starting with content '", Content2/binary, "'">>,
+
+  % :static_atoms_encoder might encode :sigil_ atoms as arbitrary terms
+  MaybeSigil = case is_atom(Atom) of
+    true -> case atom_to_binary(Atom) of
+      <<"sigil_", Chars/binary>> -> <<"\~", Chars/binary, " ">>;
+      _ -> <<>>
+    end;
+    false -> <<>>
+  end,
+
+  Message = <<"syntax error before: sigil ", MaybeSigil/binary, "starting with content '", Content2/binary, "'">>,
   raise_snippet(Location, File, Input, 'Elixir.SyntaxError', Message);
 
 %% Binaries (and interpolation) are wrapped in [<<...>>]

lib/elixir/src/elixir_expand.erl

@@ -856,10 +856,6 @@ expand_remote(Receiver, DotMeta, Right, Meta, Args, S, SL, #{context := Context}
 
     _ ->
       AttachedDotMeta = attach_context_module(Receiver, DotMeta, E),
-
-      is_atom(Receiver) andalso
-        elixir_env:trace({remote_function, Meta, Receiver, Right, length(Args)}, E),
-
       {EArgs, {SA, _}, EA} = mapfold(fun expand_arg/3, {SL, S}, E, Args),
 
       case rewrite(Context, Receiver, AttachedDotMeta, Right, Meta, EArgs, S) of

lib/elixir/src/elixir_locals.erl

@@ -118,11 +118,11 @@ format_error({function_conflict, {Receiver, {Name, Arity}}}) ->
 format_error({unused_args, {Name, Arity}}) ->
   io_lib:format("default values for the optional arguments in ~ts/~B are never used", [Name, Arity]);
 
-format_error({unused_args, {Name, Arity}, 1}) ->
-  io_lib:format("the default value for the first optional argument in ~ts/~B is never used", [Name, Arity]);
+format_error({unused_args, {Name, Arity}, Count}) when Arity - Count == 1 ->
+  io_lib:format("the default value for the last optional argument in ~ts/~B is never used", [Name, Arity]);
 
 format_error({unused_args, {Name, Arity}, Count}) ->
-  io_lib:format("the default values for the first ~B optional arguments in ~ts/~B are never used", [Count, Name, Arity]);
+  io_lib:format("the default values for the last ~B optional arguments in ~ts/~B are never used", [Arity - Count, Name, Arity]);
 
 format_error({unused_def, {Name, Arity}, defp}) ->
   io_lib:format("function ~ts/~B is unused", [Name, Arity]);

lib/elixir/src/elixir_module.erl

@@ -508,19 +508,17 @@ beam_location(ModuleAsCharlist) ->
 checker_info() ->
   case get(elixir_checker_info) of
     undefined -> undefined;
-    _ ->
-      Log =
-        case erlang:get(elixir_code_diagnostics) of
-          {_, false} -> false;
-          _ -> true
-        end,
-
-      {'Elixir.Module.ParallelChecker':get(), Log}
+    _ -> 'Elixir.Module.ParallelChecker':get()
   end.
 
 spawn_parallel_checker(undefined, _Module, _ModuleMap) ->
-  nil;
-spawn_parallel_checker({CheckerInfo, Log}, Module, ModuleMap) ->
+  ok;
+spawn_parallel_checker(CheckerInfo, Module, ModuleMap) ->
+  Log =
+    case erlang:get(elixir_code_diagnostics) of
+      {_, false} -> false;
+      _ -> true
+    end,
   'Elixir.Module.ParallelChecker':spawn(CheckerInfo, Module, ModuleMap, Log).
 
 make_module_available(Module, Binary) ->

lib/elixir/src/elixir_parser.yrl

@@ -939,11 +939,11 @@ build_access(Expr, {List, Meta}) ->
 
 %% Interpolation aware
 
-build_sigil({sigil, Location, Sigil, Parts, Modifiers, Indentation, Delimiter}) ->
+build_sigil({sigil, Location, Atom, Parts, Modifiers, Indentation, Delimiter}) ->
   Meta = meta_from_location(Location),
   MetaWithDelimiter = [{delimiter, Delimiter} | Meta],
   MetaWithIndentation = meta_with_indentation(Meta, Indentation),
-  {list_to_atom("sigil_" ++ Sigil),
+  {Atom,
    MetaWithDelimiter,
    [{'<<>>', MetaWithIndentation, string_parts(Parts)}, Modifiers]}.
 

lib/elixir/src/elixir_tokenizer.erl

@@ -1030,8 +1030,8 @@ extract_heredoc_with_interpolation(Line, Column, Scope, Interpol, T, H) ->
       end;
 
     error ->
-      Message = "heredoc allows only zero or more whitespace characters followed by a new line after ",
-      {error, {Line, Column, io_lib:format(Message, []), [H, H, H]}}
+      Message = "heredoc allows only whitespace characters followed by a new line after opening ",
+      {error, {Line, Column + 3, io_lib:format(Message, []), [H, H, H]}}
   end.
 
 extract_heredoc_header("\r\n" ++ Rest) ->
@@ -1550,7 +1550,7 @@ tokenize_sigil_name([S | T], NameAcc, Line, Column, Scope, Tokens) when ?is_upca
   tokenize_sigil_name(T, [S | NameAcc], Line, Column + 1, Scope, Tokens);
 % With a lowercase letter and a non-empty NameAcc we return an error.
 tokenize_sigil_name([S | _T] = Original, [_ | _] = NameAcc, _Line, _Column, _Scope, _Tokens) when ?is_downcase(S) ->
-  Message = "invalid sigil name, it should be either a one-letter lowercase letter or a" ++ 
+  Message = "invalid sigil name, it should be either a one-letter lowercase letter or a" ++
             " sequence of uppercase letters only, got: ",
   {error, Message, [$~] ++ lists:reverse(NameAcc) ++ Original};
 % We finished the letters, so the name is over.
@@ -1561,12 +1561,8 @@ tokenize_sigil_contents([H, H, H | T] = Original, [S | _] = SigilName, Line, Col
     when ?is_quote(H) ->
   case extract_heredoc_with_interpolation(Line, Column, Scope, ?is_downcase(S), T, H) of
     {ok, NewLine, NewColumn, Parts, Rest, NewScope} ->
-      {Final, Modifiers} = collect_modifiers(Rest, []),
       Indentation = NewColumn - 4,
-      TokenColumn = Column - 1 - length(SigilName),
-      Token = {sigil, {Line, TokenColumn, nil}, SigilName, Parts, Modifiers, Indentation, <<H, H, H>>},
-      NewColumnWithModifiers = NewColumn + length(Modifiers),
-      tokenize(Final, NewLine, NewColumnWithModifiers, NewScope, [Token | Tokens]);
+      add_sigil_token(SigilName, Line, Column, NewLine, NewColumn, Parts, Rest, NewScope, Tokens, Indentation, <<H, H, H>>);
 
     {error, Reason} ->
       error(Reason, [$~] ++ SigilName ++ Original, Scope, Tokens)
@@ -1576,12 +1572,8 @@ tokenize_sigil_contents([H | T] = Original, [S | _] = SigilName, Line, Column, S
     when ?is_sigil(H) ->
   case elixir_interpolation:extract(Line, Column + 1, Scope, ?is_downcase(S), T, sigil_terminator(H)) of
     {NewLine, NewColumn, Parts, Rest, NewScope} ->
-      {Final, Modifiers} = collect_modifiers(Rest, []),
       Indentation = nil,
-      TokenColumn = Column - 1 - length(SigilName),
-      Token = {sigil, {Line, TokenColumn, nil}, SigilName, tokens_to_binary(Parts), Modifiers, Indentation, <<H>>},
-      NewColumnWithModifiers = NewColumn + length(Modifiers),
-      tokenize(Final, NewLine, NewColumnWithModifiers, NewScope, [Token | Tokens]);
+      add_sigil_token(SigilName, Line, Column, NewLine, NewColumn, tokens_to_binary(Parts), Rest, NewScope, Tokens, Indentation, <<H>>);
 
     {error, Reason} ->
       Sigil = [$~, S, H],
@@ -1601,6 +1593,24 @@ tokenize_sigil_contents([H | _] = Original, SigilName, Line, Column, Scope, Toke
 tokenize_sigil_contents([], _SigilName, Line, Column, Scope, Tokens) ->
   tokenize([], Line, Column, Scope, Tokens).
 
+add_sigil_token(SigilName, Line, Column, NewLine, NewColumn, Parts, Rest, Scope, Tokens, Indentation, Delimiter) ->
+  TokenColumn = Column - 1 - length(SigilName),
+  MaybeEncoded = case SigilName of
+    % Single-letter sigils present no risk of atom exhaustion (limited possibilities)
+    [_Char] -> {ok, list_to_atom("sigil_" ++ SigilName)};
+    _ -> unsafe_to_atom("sigil_" ++ SigilName, Line, TokenColumn, Scope)
+  end,
+  case MaybeEncoded of
+    {ok, Atom} ->
+      {Final, Modifiers} = collect_modifiers(Rest, []),
+      Token = {sigil, {Line, TokenColumn, nil}, Atom, Parts, Modifiers, Indentation, Delimiter},
+      NewColumnWithModifiers = NewColumn + length(Modifiers),
+      tokenize(Final, NewLine, NewColumnWithModifiers, Scope, [Token | Tokens]);
+
+    {error, Reason} ->
+      error(Reason, Rest, Scope, Tokens)
+  end.
+
 %% Fail early on invalid do syntax. For example, after
 %% most keywords, after comma and so on.
 tokenize_keyword_terminator(DoLine, DoColumn, do, [{identifier, {Line, Column, Meta}, Atom} | T]) ->
@@ -1796,7 +1806,7 @@ prune_tokens([{OpType, _, _} | _] = Tokens, [], Terminators)
        OpType =:= in_match_op; OpType =:= type_op; OpType =:= dual_op; OpType =:= mult_op;
        OpType =:= power_op; OpType =:= concat_op; OpType =:= range_op; OpType =:= xor_op;
        OpType =:= pipe_op; OpType =:= stab_op; OpType =:= when_op; OpType =:= assoc_op;
-       OpType =:= rel_op; OpType =:= ternary_op ->
+       OpType =:= rel_op; OpType =:= ternary_op; OpType =:= capture_op ->
   {Tokens, Terminators};
 %%% or we traverse until the end.
 prune_tokens([_ | Tokens], Opener, Terminators) ->

lib/elixir/test/elixir/code_formatter/containers_test.exs

@@ -275,6 +275,8 @@ defmodule Code.Formatter.ContainersTest do
       assert_format "<< 1 :: 2 - unit(3) >>", "<<1::2-unit(3)>>"
       assert_format "<< 1 :: 2 * 3 - unit(4) >>", "<<1::2*3-unit(4)>>"
       assert_format "<< 1 :: 2 - unit(3) - 4 / 5 >>", "<<1::2-unit(3)-(4 / 5)>>"
+      assert_format "<<0 :: ( x - 1 ) * 5>>", "<<0::(x-1)*5>>"
+      assert_format "<<0 :: 2 * 3 * 4>>", "<<0::(2*3)*4>>"
     end
 
     test "in comprehensions" do

lib/elixir/test/elixir/code_fragment_test.exs

@@ -428,11 +428,12 @@ defmodule CodeFragmentTest do
     end
 
     test "column out of range" do
-      assert CF.surround_context("hello", {1, 20}) == :none
+      assert CF.surround_context("hello", {1, 20}) ==
+               %{begin: {1, 1}, context: {:local_or_var, ~c"hello"}, end: {1, 6}}
     end
 
     test "local_or_var" do
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo", {1, i}) == %{
                  context: {:local_or_var, ~c"hello_wo"},
                  begin: {1, 1},
@@ -440,9 +441,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("hello_wo", {1, 9}) == :none
+      assert CF.surround_context("hello_wo ", {1, 10}) == :none
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context(" hello_wo", {1, i}) == %{
                  context: {:local_or_var, ~c"hello_wo"},
                  begin: {1, 2},
@@ -450,9 +451,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context(" hello_wo", {1, 10}) == :none
+      assert CF.surround_context(" hello_wo ", {1, 11}) == :none
 
-      for i <- 1..6 do
+      for i <- 1..7 do
         assert CF.surround_context("hello!", {1, i}) == %{
                  context: {:local_or_var, ~c"hello!"},
                  begin: {1, 1},
@@ -460,9 +461,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("hello!", {1, 7}) == :none
+      assert CF.surround_context("hello! ", {1, 8}) == :none
 
-      for i <- 1..5 do
+      for i <- 1..6 do
         assert CF.surround_context("안녕_세상", {1, i}) == %{
                  context: {:local_or_var, ~c"안녕_세상"},
                  begin: {1, 1},
@@ -470,7 +471,7 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("안녕_세상", {1, 6}) == :none
+      assert CF.surround_context("안녕_세상 ", {1, 6}) == :none
 
       # Keywords are not local or var
       for keyword <- ~w(do end after catch else rescue fn true false nil)c do
@@ -484,8 +485,38 @@ defmodule CodeFragmentTest do
       end
     end
 
-    test "local call" do
+    test "local + operator" do
       for i <- 1..8 do
+        assert CF.surround_context("hello_wo+", {1, i}) == %{
+                 context: {:local_or_var, ~c"hello_wo"},
+                 begin: {1, 1},
+                 end: {1, 9}
+               }
+      end
+
+      assert CF.surround_context("hello_wo+", {1, 9}) == %{
+               begin: {1, 9},
+               context: {:operator, ~c"+"},
+               end: {1, 10}
+             }
+
+      for i <- 1..9 do
+        assert CF.surround_context("hello_wo +", {1, i}) == %{
+                 context: {:local_or_var, ~c"hello_wo"},
+                 begin: {1, 1},
+                 end: {1, 9}
+               }
+      end
+
+      assert CF.surround_context("hello_wo +", {1, 10}) == %{
+               begin: {1, 10},
+               context: {:operator, ~c"+"},
+               end: {1, 11}
+             }
+    end
+
+    test "local call" do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo(", {1, i}) == %{
                  context: {:local_call, ~c"hello_wo"},
                  begin: {1, 1},
@@ -493,9 +524,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("hello_wo(", {1, 9}) == :none
+      assert CF.surround_context("hello_wo(", {1, 10}) == :none
 
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("hello_wo (", {1, i}) == %{
                  context: {:local_call, ~c"hello_wo"},
                  begin: {1, 1},
@@ -503,9 +534,10 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("hello_wo (", {1, 9}) == :none
+      assert CF.surround_context("hello_wo (", {1, 10}) == :none
+      assert CF.surround_context("hello_wo (", {1, 11}) == :none
 
-      for i <- 1..6 do
+      for i <- 1..7 do
         assert CF.surround_context("hello!(", {1, i}) == %{
                  context: {:local_call, ~c"hello!"},
                  begin: {1, 1},
@@ -513,9 +545,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("hello!(", {1, 7}) == :none
+      assert CF.surround_context("hello!(", {1, 8}) == :none
 
-      for i <- 1..5 do
+      for i <- 1..6 do
         assert CF.surround_context("안녕_세상(", {1, i}) == %{
                  context: {:local_call, ~c"안녕_세상"},
                  begin: {1, 1},
@@ -523,7 +555,7 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("안녕_세상(", {1, 6}) == :none
+      assert CF.surround_context("안녕_세상(", {1, 7}) == :none
     end
 
     test "local arity" do
@@ -651,7 +683,7 @@ defmodule CodeFragmentTest do
     end
 
     test "alias" do
-      for i <- 1..8 do
+      for i <- 1..9 do
         assert CF.surround_context("HelloWor", {1, i}) == %{
                  context: {:alias, ~c"HelloWor"},
                  begin: {1, 1},
@@ -659,9 +691,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("HelloWor", {1, 9}) == :none
+      assert CF.surround_context("HelloWor ", {1, 10}) == :none
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context(" HelloWor", {1, i}) == %{
                  context: {:alias, ~c"HelloWor"},
                  begin: {1, 2},
@@ -669,9 +701,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context(" HelloWor", {1, 10}) == :none
+      assert CF.surround_context(" HelloWor ", {1, 11}) == :none
 
-      for i <- 1..9 do
+      for i <- 1..10 do
         assert CF.surround_context("Hello.Wor", {1, i}) == %{
                  context: {:alias, ~c"Hello.Wor"},
                  begin: {1, 1},
@@ -679,9 +711,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("Hello.Wor", {1, 10}) == :none
+      assert CF.surround_context("Hello.Wor ", {1, 11}) == :none
 
-      for i <- 1..11 do
+      for i <- 1..12 do
         assert CF.surround_context("Hello . Wor", {1, i}) == %{
                  context: {:alias, ~c"Hello.Wor"},
                  begin: {1, 1},
@@ -689,9 +721,9 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("Hello . Wor", {1, 12}) == :none
+      assert CF.surround_context("Hello . Wor ", {1, 13}) == :none
 
-      for i <- 1..15 do
+      for i <- 1..16 do
         assert CF.surround_context("Foo . Bar . Baz", {1, i}) == %{
                  context: {:alias, ~c"Foo.Bar.Baz"},
                  begin: {1, 1},
@@ -706,6 +738,14 @@ defmodule CodeFragmentTest do
                  end: {3, 5}
                }
       end
+
+      for i <- 1..11 do
+        assert CF.surround_context("Foo.Bar.Baz.foo(bar)", {1, i}) == %{
+                 context: {:alias, ~c"Foo.Bar.Baz"},
+                 begin: {1, 1},
+                 end: {1, 12}
+               }
+      end
     end
 
     test "underscored special forms" do
@@ -715,17 +755,21 @@ defmodule CodeFragmentTest do
                end: {1, 11}
              }
 
-      assert CF.surround_context("__MODULE__.Foo", {1, 12}) == %{
-               context: {:alias, {:local_or_var, ~c"__MODULE__"}, ~c"Foo"},
-               begin: {1, 1},
-               end: {1, 15}
-             }
+      for i <- 1..15 do
+        assert CF.surround_context("__MODULE__.Foo", {1, i}) == %{
+                 context: {:alias, {:local_or_var, ~c"__MODULE__"}, ~c"Foo"},
+                 begin: {1, 1},
+                 end: {1, 15}
+               }
+      end
 
-      assert CF.surround_context("__MODULE__.Foo.Sub", {1, 16}) == %{
-               context: {:alias, {:local_or_var, ~c"__MODULE__"}, ~c"Foo.Sub"},
-               begin: {1, 1},
-               end: {1, 19}
-             }
+      for i <- 1..19 do
+        assert CF.surround_context("__MODULE__.Foo.Sub", {1, i}) == %{
+                 context: {:alias, {:local_or_var, ~c"__MODULE__"}, ~c"Foo.Sub"},
+                 begin: {1, 1},
+                 end: {1, 19}
+               }
+      end
 
       assert CF.surround_context("%__MODULE__{}", {1, 5}) == %{
                context: {:struct, {:local_or_var, ~c"__MODULE__"}},
@@ -771,17 +815,21 @@ defmodule CodeFragmentTest do
     end
 
     test "attribute submodules" do
-      assert CF.surround_context("@some.Foo", {1, 8}) == %{
-               context: {:alias, {:module_attribute, ~c"some"}, ~c"Foo"},
-               begin: {1, 1},
-               end: {1, 10}
-             }
+      for i <- 1..10 do
+        assert CF.surround_context("@some.Foo", {1, i}) == %{
+                 context: {:alias, {:module_attribute, ~c"some"}, ~c"Foo"},
+                 begin: {1, 1},
+                 end: {1, 10}
+               }
+      end
 
-      assert CF.surround_context("@some.Foo.Sub", {1, 12}) == %{
-               context: {:alias, {:module_attribute, ~c"some"}, ~c"Foo.Sub"},
-               begin: {1, 1},
-               end: {1, 14}
-             }
+      for i <- 1..14 do
+        assert CF.surround_context("@some.Foo.Sub", {1, i}) == %{
+                 context: {:alias, {:module_attribute, ~c"some"}, ~c"Foo.Sub"},
+                 begin: {1, 1},
+                 end: {1, 14}
+               }
+      end
 
       assert CF.surround_context("%@some{}", {1, 5}) == %{
                context: {:struct, {:module_attribute, ~c"some"}},
@@ -858,7 +906,7 @@ defmodule CodeFragmentTest do
                end: {1, 15}
              }
 
-      for i <- 2..9 do
+      for i <- 2..10 do
         assert CF.surround_context("%HelloWor", {1, i}) == %{
                  context: {:struct, ~c"HelloWor"},
                  begin: {1, 1},
@@ -866,7 +914,7 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("%HelloWor", {1, 10}) == :none
+      assert CF.surround_context("%HelloWor ", {1, 11}) == :none
 
       # With dot
       assert CF.surround_context("%Hello.Wor", {1, 1}) == %{
@@ -875,7 +923,7 @@ defmodule CodeFragmentTest do
                end: {1, 11}
              }
 
-      for i <- 2..10 do
+      for i <- 2..11 do
         assert CF.surround_context("%Hello.Wor", {1, i}) == %{
                  context: {:struct, ~c"Hello.Wor"},
                  begin: {1, 1},
@@ -883,7 +931,7 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("%Hello.Wor", {1, 11}) == :none
+      assert CF.surround_context("%Hello.Wor ", {1, 12}) == :none
 
       # With spaces
       assert CF.surround_context("% Hello . Wor", {1, 1}) == %{
@@ -892,7 +940,7 @@ defmodule CodeFragmentTest do
                end: {1, 14}
              }
 
-      for i <- 2..13 do
+      for i <- 2..14 do
         assert CF.surround_context("% Hello . Wor", {1, i}) == %{
                  context: {:struct, ~c"Hello.Wor"},
                  begin: {1, 1},
@@ -900,7 +948,7 @@ defmodule CodeFragmentTest do
                }
       end
 
-      assert CF.surround_context("% Hello . Wor", {1, 14}) == :none
+      assert CF.surround_context("% Hello . Wor ", {1, 15}) == :none
     end
 
     test "module attributes" do
@@ -1098,6 +1146,8 @@ defmodule CodeFragmentTest do
 
     test "keeps operators" do
       assert cc2q("1 + 2") == s2q("1 + __cursor__()")
+      assert cc2q("&foo") == s2q("&__cursor__()")
+      assert cc2q("&foo/") == s2q("&foo/__cursor__()")
     end
 
     test "keeps function calls without parens" do
@@ -1200,11 +1250,6 @@ defmodule CodeFragmentTest do
       assert cc2q("(fn x, y -> x + y end") == s2q("(__cursor__())")
     end
 
-    test "removes captures" do
-      assert cc2q("[& &1") == s2q("[__cursor__()]")
-      assert cc2q("[&(&1") == s2q("[__cursor__()]")
-    end
-
     test "removes closed terminators" do
       assert cc2q("foo([1, 2, 3]") == s2q("foo(__cursor__())")
       assert cc2q("foo({1, 2, 3}") == s2q("foo(__cursor__())")

lib/elixir/test/elixir/code_normalizer/quoted_ast_test.exs

@@ -226,6 +226,11 @@ defmodule Code.Normalizer.QuotedASTTest do
       assert quoted_to_string(quoted) <> "\n" == expected
     end
 
+    test "invalid block" do
+      assert quoted_to_string({:__block__, [], {:bar, [], []}}) ==
+               "{:__block__, [], {:bar, [], []}}"
+    end
+
     test "not in" do
       assert quoted_to_string(quote(do: false not in [])) == "false not in []"
     end

lib/elixir/test/elixir/code_test.exs

@@ -90,6 +90,28 @@ defmodule CodeTest do
                  Code.eval_quoted(quoted, [])
                end)
     end
+
+    test "captures unknown local calls" do
+      sample = """
+      defmodule CodeTest.UnknownLocalCall do
+        def perform do
+          foo()
+        end
+      end
+      """
+
+      assert {:rescued, [%{message: message}]} =
+               Code.with_diagnostics(fn ->
+                 try do
+                   quoted = Code.string_to_quoted!(sample, columns: true)
+                   Code.eval_quoted(quoted, [])
+                 rescue
+                   _ -> :rescued
+                 end
+               end)
+
+      assert message =~ "undefined function foo/0"
+    end
   end
 
   describe "eval_string/1,2,3" do
@@ -325,7 +347,12 @@ defmodule CodeTest do
       assert env.versioned_vars == %{}
 
       assert_receive {:trace, {:on_module, _, _}, %{module: CodeTest.TracingPruning} = trace_env}
-      assert trace_env.versioned_vars == %{{:result, Kernel} => 5, {:x, nil} => 1, {:y, nil} => 4}
+
+      assert trace_env.versioned_vars == %{
+               {:result, :elixir_compiler} => 5,
+               {:x, nil} => 1,
+               {:y, nil} => 4
+             }
     end
 
     test "with defguard" do
@@ -474,6 +501,14 @@ defmodule CodeTest do
       :code.purge(CompileCrossSample)
       :code.delete(CompileCrossSample)
     end
+
+    test "disables tail call optimization at the root" do
+      try do
+        Code.compile_string("List.flatten(123)")
+      rescue
+        _ -> assert Enum.any?(__STACKTRACE__, &match?({_, :__FILE__, 1, _}, &1))
+      end
+    end
   end
 
   test "format_string/2 returns empty iodata for empty string" do

lib/elixir/test/elixir/enum_test.exs

@@ -1102,6 +1102,16 @@ defmodule EnumTest do
              [2, 1, 3]
   end
 
+  test "slice on MapSets" do
+    assert MapSet.new(1..10) |> Enum.slice(0, 2) |> Enum.count() == 2
+    assert MapSet.new(1..3) |> Enum.slice(0, 10) |> Enum.count() == 3
+    assert MapSet.new(1..10) |> Enum.slice(0..1) |> Enum.count() == 2
+    assert MapSet.new(1..3) |> Enum.slice(0..10) |> Enum.count() == 3
+
+    assert MapSet.new(1..10) |> Enum.slice(0..4//2) |> Enum.count() == 3
+    assert MapSet.new(1..10) |> Enum.slice(0..5//2) |> Enum.count() == 3
+  end
+
   test "sort/1" do
     assert Enum.sort([5, 3, 2, 4, 1]) == [1, 2, 3, 4, 5]
   end

lib/elixir/test/elixir/kernel/docs_test.exs

@@ -381,4 +381,30 @@ defmodule Kernel.DocsTest do
              {{:fuz, 0}, :none}
            ] = Enum.sort(function_docs)
   end
+
+  test "generated functions are annotated as such" do
+    write_beam(
+      defmodule ToBeUsed do
+        defmacro __using__(_) do
+          quote do
+            @doc "Hello"
+            def foo, do: :bar
+          end
+        end
+      end
+    )
+
+    write_beam(
+      defmodule WillBeUsing do
+        use ToBeUsed
+      end
+    )
+
+    {:docs_v1, _, _, _, _, _, docs} = Code.fetch_docs(WillBeUsing)
+
+    assert [
+             {{:function, :foo, 0}, [generated: true, location: 399], ["foo()"],
+              %{"en" => "Hello"}, %{}}
+           ] = docs
+  end
 end

lib/elixir/test/elixir/kernel/parser_test.exs

@@ -182,6 +182,9 @@ defmodule Kernel.ParserTest do
       assert Code.string_to_quoted(":there_is_no_such_atom", existing_atoms_only: true) ==
                {:error,
                 {[line: 1, column: 1], "unsafe atom does not exist: ", "there_is_no_such_atom"}}
+
+      assert Code.string_to_quoted("~UNKNOWN'foo bar'", existing_atoms_only: true) ==
+               {:error, {[line: 1, column: 1], "unsafe atom does not exist: ", "sigil_UNKNOWN"}}
     end
 
     test "encodes atoms" do
@@ -228,6 +231,20 @@ defmodule Kernel.ParserTest do
                )
     end
 
+    test "encodes multi-letter sigils" do
+      ref = make_ref()
+
+      encoder = fn atom, meta ->
+        assert atom == "sigil_UNKNOWN"
+        assert meta[:line] == 1
+        assert meta[:column] == 1
+        {:ok, ref}
+      end
+
+      assert {:ok, {^ref, [delimiter: "'", line: 1], [{:<<>>, [line: 1], ["abc"]}, []]}} =
+               Code.string_to_quoted("~UNKNOWN'abc'", static_atoms_encoder: encoder)
+    end
+
     test "addresses ambiguities" do
       encoder = fn string, _meta -> {:ok, {:atom, string}} end
 
@@ -254,6 +271,16 @@ defmodule Kernel.ParserTest do
                Code.string_to_quoted("[do: 1, true: 2, end: 3]", static_atoms_encoder: encoder)
     end
 
+    test "does not encode one-letter sigils" do
+      encoder = fn atom, _meta -> raise "shouldn't be invoked for #{atom}" end
+
+      assert {:ok, {:sigil_z, [{:delimiter, "'"}, {:line, 1}], [{:<<>>, [line: 1], ["foo"]}, []]}} =
+               Code.string_to_quoted("~z'foo'", static_atoms_encoder: encoder)
+
+      assert {:ok, {:sigil_Z, [{:delimiter, "'"}, {:line, 1}], [{:<<>>, [line: 1], ["foo"]}, []]}} =
+               Code.string_to_quoted("~Z'foo'", static_atoms_encoder: encoder)
+    end
+
     test "returns errors on long atoms even when using static_atoms_encoder" do
       atom = String.duplicate("a", 256)
 
@@ -271,6 +298,9 @@ defmodule Kernel.ParserTest do
 
       assert {:error, {[line: 1, column: 1], "Invalid atom name: ", "there_is_no_such_atom"}} =
                Code.string_to_quoted(":there_is_no_such_atom", static_atoms_encoder: encoder)
+
+      assert {:error, {[line: 1, column: 1], "Invalid atom name: ", "sigil_UNKNOWN"}} =
+               Code.string_to_quoted("~UNKNOWN'foo bar'", static_atoms_encoder: encoder)
     end
 
     test "may return tuples" do
@@ -538,7 +568,7 @@ defmodule Kernel.ParserTest do
   describe "syntax errors" do
     test "invalid heredoc start" do
       assert_syntax_error(
-        ~r/nofile:1:1: heredoc allows only zero or more whitespace characters followed by a new line after \"\"\"/,
+        ~r/nofile:1:4: heredoc allows only whitespace characters followed by a new line after opening \"\"\"/,
         ~c"\"\"\"bar\n\"\"\""
       )
     end

lib/elixir/test/elixir/kernel/raise_test.exs

@@ -224,6 +224,17 @@ defmodule Kernel.RaiseTest do
       assert result == "an exception"
     end
 
+    test "named function clause (stacktrace) or runtime (no stacktrace) error" do
+      result =
+        try do
+          Access.get("foo", 0)
+        rescue
+          x in [FunctionClauseError, CaseClauseError] -> Exception.message(x)
+        end
+
+      assert result == "no function clause matching in Access.get/3"
+    end
+
     test "with higher precedence than catch" do
       result =
         try do

lib/elixir/test/elixir/kernel/tracers_test.exs

@@ -118,6 +118,7 @@ defmodule Kernel.TracersTest do
     require Integer
     true = Integer.is_odd(1)
     {1, ""} = Integer.parse("1")
+    "foo" = Atom.to_string(:foo)
     """)
 
     assert_receive {{:remote_macro, meta, Integer, :is_odd, 1}, _}
@@ -127,6 +128,10 @@ defmodule Kernel.TracersTest do
     assert_receive {{:remote_function, meta, Integer, :parse, 1}, _}
     assert meta[:line] == 3
     assert meta[:column] == 19
+
+    assert_receive {{:remote_function, meta, Atom, :to_string, 1}, _}
+    assert meta[:line] == 4
+    assert meta[:column] == 14
   end
 
   test "traces remote via captures" do

lib/elixir/test/elixir/kernel/warning_test.exs

@@ -563,17 +563,17 @@ defmodule Kernel.WarningTest do
              end
              """)
            end) =~
-             "the default values for the first 2 optional arguments in b/3 are never used\n  nofile:3"
+             "the default value for the last optional argument in b/3 is never used\n  nofile:3"
 
     assert capture_err(fn ->
              Code.eval_string(~S"""
              defmodule Sample3 do
-               def a, do: b(1)
-               defp b(arg1 \\ 1, arg2 \\ 2, arg3 \\ 3), do: [arg1, arg2, arg3]
+               def a, do: b(1, 2)
+               defp b(arg1, arg2 \\ 2, arg3 \\ 3, arg4 \\ 4), do: [arg1, arg2, arg3, arg4]
              end
              """)
            end) =~
-             "the default value for the first optional argument in b/3 is never used\n  nofile:3"
+             "the default values for the last 2 optional arguments in b/4 are never used"
 
     assert capture_err(fn ->
              Code.eval_string(~S"""
@@ -587,17 +587,6 @@ defmodule Kernel.WarningTest do
     assert capture_err(fn ->
              Code.eval_string(~S"""
              defmodule Sample5 do
-               def a, do: b(1, 2, 3)
-               defp b(arg1 \\ 1, arg2 \\ 2, arg3 \\ 3)
-
-               defp b(arg1, arg2, arg3), do: [arg1, arg2, arg3]
-             end
-             """)
-           end) =~ "default values for the optional arguments in b/3 are never used\n  nofile:3"
-
-    assert capture_err(fn ->
-             Code.eval_string(~S"""
-             defmodule Sample6 do
                def a, do: b(1, 2)
                defp b(arg1 \\ 1, arg2 \\ 2, arg3 \\ 3)
 
@@ -605,9 +594,9 @@ defmodule Kernel.WarningTest do
              end
              """)
            end) =~
-             "the default values for the first 2 optional arguments in b/3 are never used\n  nofile:3"
+             "the default value for the last optional argument in b/3 is never used\n  nofile:3"
   after
-    purge([Sample1, Sample2, Sample3, Sample4, Sample5, Sample6])
+    purge([Sample1, Sample2, Sample3, Sample4, Sample5])
   end
 
   test "unused import" do

lib/elixir/test/elixir/kernel_test.exs

@@ -831,11 +831,25 @@ defmodule KernelTest do
     end
 
     test "matching attribute" do
-      assert_raise ArgumentError, ~r"invalid write attribute syntax", fn ->
+      assert_raise ArgumentError, ~r"invalid usage of module attributes", fn ->
         defmodule MatchAttributeInModule do
           @foo = 42
         end
       end
+
+      assert_raise ArgumentError, ~r"invalid usage of module attributes", fn ->
+        defmodule MatchAttributeInModule do
+          @foo 16
+          <<_::@foo>> = "ab"
+        end
+      end
+
+      assert_raise ArgumentError, ~r"invalid usage of module attributes", fn ->
+        defmodule MatchAttributeInModule do
+          @foo 16
+          <<_::size(@foo)>> = "ab"
+        end
+      end
     end
   end
 

lib/elixir/test/elixir/uri_test.exs

@@ -277,6 +277,32 @@ defmodule URITest do
     test "preserves an empty query" do
       assert URI.new!("http://foo.com/?").query == ""
     end
+
+    test "without scheme, undefined port after host translates to nil" do
+      assert URI.new!("//https://www.example.com") ==
+               %URI{
+                 scheme: nil,
+                 userinfo: nil,
+                 host: "https",
+                 port: nil,
+                 path: "//www.example.com",
+                 query: nil,
+                 fragment: nil
+               }
+    end
+
+    test "with scheme, undefined port after host translates to nil" do
+      assert URI.new!("myscheme://myhost:/path/info") ==
+               %URI{
+                 scheme: "myscheme",
+                 userinfo: nil,
+                 host: "myhost",
+                 port: nil,
+                 path: "/path/info",
+                 query: nil,
+                 fragment: nil
+               }
+    end
   end
 
   test "http://http://http://@http://http://?http://#http://" do

lib/elixir/test/erlang/tokenizer_test.erl

@@ -261,22 +261,22 @@ vc_merge_conflict_test() ->
     tokenize_error("<<<<<<< HEAD\n[1, 2, 3]").
 
 sigil_terminator_test() ->
-  [{sigil, {1, 1, nil}, "r", [<<"foo">>], "", nil, <<"/">>}] = tokenize("~r/foo/"),
-  [{sigil, {1, 1, nil}, "r", [<<"foo">>], "", nil, <<"[">>}] = tokenize("~r[foo]"),
-  [{sigil, {1, 1, nil}, "r", [<<"foo">>], "", nil, <<"\"">>}] = tokenize("~r\"foo\""),
-  [{sigil, {1, 1, nil}, "r", [<<"foo">>], "", nil, <<"/">>},
+  [{sigil, {1, 1, nil}, sigil_r, [<<"foo">>], "", nil, <<"/">>}] = tokenize("~r/foo/"),
+  [{sigil, {1, 1, nil}, sigil_r, [<<"foo">>], "", nil, <<"[">>}] = tokenize("~r[foo]"),
+  [{sigil, {1, 1, nil}, sigil_r, [<<"foo">>], "", nil, <<"\"">>}] = tokenize("~r\"foo\""),
+  [{sigil, {1, 1, nil}, sigil_r, [<<"foo">>], "", nil, <<"/">>},
    {comp_op, {1, 9, nil}, '=='},
    {identifier, {1, 12, _}, bar}] = tokenize("~r/foo/ == bar"),
-  [{sigil, {1, 1, nil}, "r", [<<"foo">>], "iu", nil, <<"/">>},
+  [{sigil, {1, 1, nil}, sigil_r, [<<"foo">>], "iu", nil, <<"/">>},
    {comp_op, {1, 11, nil}, '=='},
    {identifier, {1, 14, _}, bar}] = tokenize("~r/foo/iu == bar"),
-  [{sigil, {1, 1, nil}, "M", [<<"1 2 3">>], "u8", nil, <<"[">>}] = tokenize("~M[1 2 3]u8").
+  [{sigil, {1, 1, nil}, sigil_M, [<<"1 2 3">>], "u8", nil, <<"[">>}] = tokenize("~M[1 2 3]u8").
 
 sigil_heredoc_test() ->
-  [{sigil, {1, 1, nil}, "S", [<<"sigil heredoc\n">>], "", 0, <<"\"\"\"">>}] = tokenize("~S\"\"\"\nsigil heredoc\n\"\"\""),
-  [{sigil, {1, 1, nil}, "S", [<<"sigil heredoc\n">>], "", 0, <<"'''">>}] = tokenize("~S'''\nsigil heredoc\n'''"),
-  [{sigil, {1, 1, nil}, "S", [<<"sigil heredoc\n">>], "", 2, <<"\"\"\"">>}] = tokenize("~S\"\"\"\n  sigil heredoc\n  \"\"\""),
-  [{sigil, {1, 1, nil}, "s", [<<"sigil heredoc\n">>], "", 2, <<"\"\"\"">>}] = tokenize("~s\"\"\"\n  sigil heredoc\n  \"\"\"").
+  [{sigil, {1, 1, nil}, sigil_S, [<<"sigil heredoc\n">>], "", 0, <<"\"\"\"">>}] = tokenize("~S\"\"\"\nsigil heredoc\n\"\"\""),
+  [{sigil, {1, 1, nil}, sigil_S, [<<"sigil heredoc\n">>], "", 0, <<"'''">>}] = tokenize("~S'''\nsigil heredoc\n'''"),
+  [{sigil, {1, 1, nil}, sigil_S, [<<"sigil heredoc\n">>], "", 2, <<"\"\"\"">>}] = tokenize("~S\"\"\"\n  sigil heredoc\n  \"\"\""),
+  [{sigil, {1, 1, nil}, sigil_s, [<<"sigil heredoc\n">>], "", 2, <<"\"\"\"">>}] = tokenize("~s\"\"\"\n  sigil heredoc\n  \"\"\"").
 
 invalid_sigil_delimiter_test() ->
   {1, 1, "invalid sigil delimiter: ", Message} = tokenize_error("~s\\"),

lib/ex_unit/lib/ex_unit/callbacks.ex

@@ -549,14 +549,7 @@ defmodule ExUnit.Callbacks do
       end
 
     child_spec = Supervisor.child_spec(child_spec_or_module, opts)
-
-    case Supervisor.start_child(sup, child_spec) do
-      {:error, {:already_started, _pid}} ->
-        {:error, {:duplicate_child_name, child_spec.id}}
-
-      other ->
-        other
-    end
+    Supervisor.start_child(sup, child_spec)
   end
 
   @doc """

lib/ex_unit/lib/ex_unit/capture_server.ex

@@ -71,11 +71,11 @@ defmodule ExUnit.CaptureServer do
     refs = Map.put(config.log_captures, ref, true)
 
     {level, opts} = Keyword.pop(opts, :level)
-    true = :ets.insert(@ets, {ref, string_io, level || :all})
+    {formatter_mod, formatter_config} = Logger.default_formatter(opts)
+    true = :ets.insert(@ets, {ref, string_io, level || :all, formatter_mod, formatter_config})
 
     if map_size(refs) == 1 do
-      formatter = Logger.default_formatter(opts)
-      :ok = :logger.add_handler(@name, __MODULE__, %{formatter: formatter})
+      :ok = :logger.add_handler(@name, __MODULE__, %{})
 
       status =
         with {:ok, config} <- :logger.get_handler_config(:default),
@@ -226,13 +226,20 @@ defmodule ExUnit.CaptureServer do
 
   ## :logger handler callback.
 
-  def log(event, %{} = config) do
-    %{formatter: {formatter_mod, formatter_config}} = config
-    chardata = formatter_mod.format(event, formatter_config)
-
-    for [string_io, level] <- :ets.match(@ets, {:_, :"$1", :"$2"}),
+  def log(event, _config) do
+    for {_ref, string_io, level, formatter_mod, formatter_config} <- :ets.tab2list(@ets),
         :logger.compare_levels(event.level, level) in [:gt, :eq] do
-      :ok = IO.write(string_io, chardata)
+      chardata = formatter_mod.format(event, formatter_config)
+      # There is a race condition where the capture_log is removed
+      # but another process is attempting to log to string io device
+      # that no longer exists, so we wrap it in try/catch.
+      try do
+        IO.write(string_io, chardata)
+      rescue
+        _ -> :ok
+      end
     end
+
+    :ok
   end
 end

lib/ex_unit/lib/ex_unit/case.ex

@@ -167,6 +167,9 @@ defmodule ExUnit.Case do
 
     * `:doctest_data` - additional metadata about doctests (if a doctest)
 
+    * `:test_type` - the test type used when printing test results.
+      It is set by ExUnit to `:test`, `:doctest` and so on, but is customizable.
+
   The following tags customize how tests behave:
 
     * `:capture_log` - see the "Log Capture" section below
@@ -178,9 +181,6 @@ defmodule ExUnit.Case do
 
     * `:tmp_dir` - (since v1.11.0) see the "Tmp Dir" section below
 
-    * `:test_type` - the test type used when printing test results.
-      It is set by ExUnit to `:test`, `:doctest` and so on, but is customizable.
-
   ## Filters
 
   Tags can also be used to identify specific tests, which can then

lib/ex_unit/lib/ex_unit/case_template.ex

@@ -130,7 +130,7 @@ defmodule ExUnit.CaseTemplate do
   The second argument passed to `use MyCase` gets forwarded to `using/2` too:
 
       defmodule SomeTestCase do
-        use MyCase, async: true, import_helpers: true, async: true
+        use MyCase, async: true, import_helpers: true
 
         test "the truth" do
           # truth/0 comes from MyApp.TestHelpers:

lib/ex_unit/lib/ex_unit/diff.ex

@@ -200,11 +200,15 @@ defmodule ExUnit.Diff do
 
       {diff, env}
     else
-      diff_value(left, right, env)
+      non_recursive_diff_value(left, right, env)
     end
   end
 
   defp diff_value(left, right, env) do
+    non_recursive_diff_value(left, right, env)
+  end
+
+  defp non_recursive_diff_value(left, right, env) do
     diff_left = escape(left) |> update_diff_meta(true)
     diff_right = escape(right) |> update_diff_meta(true)
     diff = %__MODULE__{equivalent?: false, left: diff_left, right: diff_right}

lib/ex_unit/lib/ex_unit/doc_test.ex

@@ -382,9 +382,15 @@ defmodule ExUnit.DocTest do
     last_expr = Macro.to_string(last_expr(expr_ast))
 
     quote do
+      # `expr_ast` may introduce variables that may be
+      # used within `expected_ast` so they both need to
+      # unquoted together here
+      value = unquote(expr_ast)
+      expected_value = unquote(expected_ast)
+
       ExUnit.DocTest.__test__(
-        unquote(expr_ast),
-        unquote(expected_ast),
+        value,
+        expected_value,
         unquote(doctest),
         unquote(last_expr),
         unquote(expected),
@@ -624,57 +630,37 @@ defmodule ExUnit.DocTest do
     end
   end
 
-  defp adjust_indent(kind, [line | rest], line_no, adjusted_lines, indent, module)
-       when kind in [:prompt, :after_prompt] do
+  defp adjust_indent(kind, [line | rest], line_no, adjusted_lines, indent, module) do
     stripped_line = strip_indent(line, indent)
+    trimmed_line = String.trim_leading(line)
 
-    case String.trim_leading(line) do
-      "" ->
-        :ok
+    if kind != :code and trimmed_line != stripped_line do
+      n_spaces = if indent == 1, do: "#{indent} space", else: "#{indent} spaces"
 
-      ^stripped_line ->
-        :ok
+      raise Error,
+        line: line_no,
+        module: module,
+        message: """
+        indentation level mismatch on doctest line: #{inspect(line)}
 
-      _ ->
-        n_spaces = if indent == 1, do: "#{indent} space", else: "#{indent} spaces"
+        If you are planning to assert on the result of an `iex>` expression, \
+        make sure the result is indented at the beginning of `iex>`, which \
+        in this case is exactly #{n_spaces}.
 
-        raise Error,
-          line: line_no,
-          module: module,
-          message: """
-          indentation level mismatch on doctest line: #{inspect(line)}
-
-          If you are planning to assert on the result of an `iex>` expression, \
-          make sure the result is indented at the beginning of `iex>`, which \
-          in this case is exactly #{n_spaces}.
-
-          If instead you have an `iex>` expression that spans over multiple lines, \
-          please make sure that each line after the first one begins with `...>`.
-          """
+        If instead you have an `iex>` expression that spans over multiple lines, \
+        please make sure that each line after the first one begins with `...>`.
+        """
     end
 
-    adjusted_lines = [{adjust_prompt(stripped_line, line_no, module), line_no} | adjusted_lines]
-
-    next =
-      cond do
-        kind == :prompt -> :after_prompt
-        String.starts_with?(stripped_line, @iex_prompt ++ @dot_prompt) -> :after_prompt
-        true -> :code
-      end
-
-    adjust_indent(next, rest, line_no + 1, adjusted_lines, indent, module)
-  end
-
-  defp adjust_indent(:code, [line | rest], line_no, adjusted_lines, indent, module) do
-    stripped_line = strip_indent(line, indent)
-
     cond do
       stripped_line == "" or String.starts_with?(stripped_line, @fences) ->
         adjusted_lines = [{"", line_no} | adjusted_lines]
         adjust_indent(:text, rest, line_no + 1, adjusted_lines, 0, module)
 
-      String.starts_with?(String.trim_leading(stripped_line), @iex_prompt) ->
-        adjust_indent(:prompt, [line | rest], line_no, adjusted_lines, indent, module)
+      kind == :prompt or String.starts_with?(trimmed_line, @iex_prompt) or
+          (kind == :maybe_prompt and String.starts_with?(trimmed_line, @dot_prompt)) ->
+        line = {adjust_prompt(stripped_line, line_no, module), line_no}
+        adjust_indent(:maybe_prompt, rest, line_no + 1, [line | adjusted_lines], indent, module)
 
       true ->
         adjusted_lines = [{stripped_line, line_no} | adjusted_lines]

lib/ex_unit/lib/ex_unit/runner.ex

@@ -293,8 +293,9 @@ defmodule ExUnit.Runner do
           {test_module, invalid_tests, []}
 
         {:DOWN, ^module_ref, :process, ^module_pid, error} ->
+          invalid_tests = Enum.map(tests, &%{&1 | state: {:invalid, test_module}})
           test_module = %{test_module | state: failed({:EXIT, module_pid}, error, [])}
-          {test_module, [], []}
+          {test_module, invalid_tests, []}
       end
 
     timeout = get_timeout(config, %{})

lib/ex_unit/test/ex_unit/callbacks_test.exs

@@ -124,6 +124,22 @@ defmodule ExUnit.CallbacksTest do
              "** (MatchError) no match of right hand side value: :error"
   end
 
+  test "doesn't choke on setup_all exits" do
+    defmodule SetupAllExitTest do
+      use ExUnit.Case
+
+      setup_all _ do
+        Process.exit(self(), :error)
+      end
+
+      test "ok" do
+        assert true
+      end
+    end
+
+    assert capture_io(fn -> ExUnit.run() end) =~ "1 test, 0 failures, 1 invalid"
+  end
+
   test "doesn't choke on dead supervisor" do
     defmodule StartSupervisedErrorTest do
       use ExUnit.Case

lib/ex_unit/test/ex_unit/capture_log_test.exs

@@ -114,6 +114,19 @@ defmodule ExUnit.CaptureLogTest do
 
       assert log == "id=123 | hello"
     end
+
+    @tag capture_log: true
+    test "respect options with capture_log: true" do
+      options = [format: "$metadata| $message", metadata: [:id], colors: [enabled: false]]
+
+      assert {4, log} =
+               with_log(options, fn ->
+                 Logger.info("hello", id: 123)
+                 2 + 2
+               end)
+
+      assert log == "id=123 | hello"
+    end
   end
 
   defp wait_capture_removal() do

lib/ex_unit/test/ex_unit/diff_test.exs

@@ -1121,6 +1121,8 @@ defmodule ExUnit.DiffTest do
     )
   end
 
+  @compile {:no_warn_undefined, String}
+
   test "functions" do
     identity = & &1
     inspect = inspect(identity)
@@ -1130,11 +1132,15 @@ defmodule ExUnit.DiffTest do
 
     refute_diff(identity == :a, "-#{inspect}-", "+:a+")
     refute_diff({identity, identity} == :a, "-{#{inspect}, #{inspect}}", "+:a+")
-
     refute_diff({identity, :a} == {:a, identity}, "{-#{inspect}-, -:a-}", "{+:a+, +#{inspect}+}")
-
     refute_diff(%{identity => identity} == :a, "-%{#{inspect} => #{inspect}}", "+:a+")
 
+    refute_diff(
+      (&String.to_charlist/1) == (&String.unknown/1),
+      "-&String.to_charlist/1-",
+      "+&String.unknown/1"
+    )
+
     refute_diff(
       %Opaque{data: identity} == :a,
       "-#Opaque<???>-",

lib/ex_unit/test/ex_unit/doc_test_test.exs

@@ -317,8 +317,7 @@ defmodule ExUnit.DocTestTest.FencedHeredocs do
   ```
 
       ```
-      iex> 1 + 2
-      3
+      iex> 3 = 1 + 2
       ```
 
   ```
@@ -444,6 +443,16 @@ defmodule ExUnit.DocTestTest.Haiku do
 end
 |> ExUnit.BeamHelpers.write_beam()
 
+defmodule ExUnit.DocTestTest.VariableInExpectation do
+  @doc """
+  iex> num = 1
+  iex> ExUnit.DocTestTest.VariableInExpectation.inc(num)
+  num + 1
+  """
+  def inc(num), do: num + 1
+end
+|> ExUnit.BeamHelpers.write_beam()
+
 defmodule ExUnit.DocTestTest.PatternMatching do
   def starting_line, do: __ENV__.line + 2
 
@@ -507,6 +516,7 @@ defmodule ExUnit.DocTestTest do
   doctest ExUnit.DocTestTest.IndentationHeredocs
   doctest ExUnit.DocTestTest.FencedHeredocs
   doctest ExUnit.DocTestTest.Haiku
+  doctest ExUnit.DocTestTest.VariableInExpectation
 
   import ExUnit.CaptureIO
 

lib/ex_unit/test/ex_unit/formatter_test.exs

@@ -491,28 +491,25 @@ defmodule ExUnit.FormatterTest do
   test "inspect failure" do
     failure = [{:error, catch_assertion(assert :will_fail == %BadInspect{}), []}]
 
-    message = ~S'''
-      got FunctionClauseError with message:
-
-          """
-          no function clause matching in Inspect.ExUnit.FormatterTest.BadInspect.inspect/2
-          """
-
-      while inspecting:
-
-          %{__struct__: ExUnit.FormatterTest.BadInspect, key: 0}
-
-      Stacktrace:
-    '''
-
-    assert format_test_failure(test(), failure, 1, 80, &formatter/2) =~ """
+    assert format_test_failure(test(), failure, 1, 80, &formatter/2) =~ ~s'''
              1) world (Hello)
                 test/ex_unit/formatter_test.exs:1
                 Assertion with == failed
                 code:  assert :will_fail == %BadInspect{}
                 left:  :will_fail
-                right: #Inspect.Error<\n#{message}\
-           """
+                right: #Inspect.Error<
+             got FunctionClauseError with message:
+
+                 """
+                 no function clause matching in Inspect.ExUnit.FormatterTest.BadInspect.inspect/2
+                 """
+
+             while inspecting:
+
+                 #{inspect(%BadInspect{}, structs: false)}
+
+             Stacktrace:
+           '''
   end
 
   defmodule BadMessage do

lib/ex_unit/test/ex_unit/supervised_test.exs

@@ -73,19 +73,14 @@ defmodule ExUnit.SupervisedTest do
 
   test "starts a supervised process with ID checks" do
     {:ok, pid} = start_supervised({MyAgent, 0})
+    assert is_pid(pid)
 
-    assert {:error, {:duplicate_child_name, ExUnit.SupervisedTest.MyAgent}} =
-             start_supervised({MyAgent, 0})
-
-    assert {:error, {{:already_started, ^pid}, _}} = start_supervised({MyAgent, 0}, id: :another)
+    assert {:error, _} = start_supervised({MyAgent, 0})
+    assert {:error, _} = start_supervised({MyAgent, 0}, id: :another)
 
     assert_raise RuntimeError, ~r"Reason: bad child specification", fn ->
       start_supervised!(%{id: 1, start: :oops})
     end
-
-    assert_raise RuntimeError, ~r"Reason: already started", fn ->
-      start_supervised!({MyAgent, 0}, id: :another)
-    end
   end
 
   test "stops a supervised process" do

lib/iex/lib/iex.ex

@@ -536,6 +536,9 @@ defmodule IEx do
 
   @doc """
   Returns `true` if IEx was started, `false` otherwise.
+
+  This means the IEx application was started, but not
+  that its CLI interface is running.
   """
   @spec started?() :: boolean()
   def started? do
@@ -579,9 +582,6 @@ defmodule IEx do
   @doc """
   Pries into the process environment.
 
-  When you start `iex`, IEx will set this function to be the
-  default `dbg/2` backend unless the `--no-pry` flag is given.
-
   This function is useful for debugging a particular chunk of code
   when executed by a particular process. The process becomes
   the evaluator of IEx commands and is temporarily changed to
@@ -597,6 +597,11 @@ defmodule IEx do
 
   See also `break!/4` for others ways to pry.
 
+  > #### `dbg/0` integration
+  >
+  > By calling `iex --dbg pry`, `iex` will set this function
+  > as the default backend for `dbg/0` calls.
+
   ## Examples
 
   Let's suppose you want to investigate what is happening
@@ -857,6 +862,8 @@ defmodule IEx do
 
   # This is a callback invoked by Erlang shell utilities
   # when someone presses Ctrl+G and adds `s 'Elixir.IEx'`.
+  # Let's consider exposing this as iex:start() and rename
+  # elixir:start_iex() to iex:cli().
   @doc false
   def start(opts \\ [], mfa \\ {IEx, :dont_display_result, []}) do
     # TODO: Keep only this branch, delete optional args and mfa,
@@ -864,15 +871,19 @@ defmodule IEx do
     if Code.ensure_loaded?(:prim_tty) do
       spawn(fn ->
         {:ok, _} = Application.ensure_all_started(:iex)
+        :ok = :io.setopts(binary: true, encoding: :unicode)
         _ = for fun <- Enum.reverse(after_spawn()), do: fun.()
         IEx.Server.run([register: false] ++ opts)
       end)
     else
       spawn(fn ->
-        {:ok, _} = Application.ensure_all_started(:elixir)
-        System.wait_until_booted()
-        :ok = :io.setopts(binary: true, encoding: :unicode)
+        case :init.notify_when_started(self()) do
+          :started -> :ok
+          _ -> :init.wait_until_started()
+        end
+
         {:ok, _} = Application.ensure_all_started(:iex)
+        :ok = :io.setopts(binary: true, encoding: :unicode)
         _ = for fun <- Enum.reverse(after_spawn()), do: fun.()
         IEx.Server.run_from_shell(opts, mfa)
       end)
@@ -920,13 +931,18 @@ defmodule IEx do
         mfa
       end
 
-    :ok = :shell.start_interactive(shell)
+    case :shell.start_interactive(shell) do
+      :ok ->
+        receive do
+          {^ref, shell} -> shell
+        after
+          15_000 ->
+            IO.puts(:stderr, "Could not start IEx CLI due to reason: :boot_timeout")
+            System.halt(1)
+        end
 
-    receive do
-      {^ref, shell} -> shell
-    after
-      15_000 ->
-        IO.puts(:stderr, "Could not start the shell after 15 seconds, aborting...")
+      {:error, reason} ->
+        IO.puts(:stderr, "Could not start IEx CLI due to reason: #{inspect(reason)}")
         System.halt(1)
     end
   end

lib/iex/lib/iex/autocomplete.ex

@@ -146,7 +146,7 @@ defmodule IEx.Autocomplete do
 
   @doc false
   def exports(mod) do
-    if Code.ensure_loaded?(mod) and function_exported?(mod, :__info__, 1) do
+    if ensure_loaded?(mod) and function_exported?(mod, :__info__, 1) do
       mod.__info__(:macros) ++ (mod.__info__(:functions) -- [__info__: 1])
     else
       mod.module_info(:exports) -- [module_info: 0, module_info: 1]
@@ -313,21 +313,23 @@ defmodule IEx.Autocomplete do
       for {alias, mod} <- aliases_from_env(shell),
           [name] = Module.split(alias),
           String.starts_with?(name, hint),
-          struct?(mod) and not function_exported?(mod, :exception, 1),
-          do: %{kind: :struct, name: name}
+          do: {mod, name}
 
     modules =
       for "Elixir." <> name = full_name <- match_modules("Elixir." <> hint, true),
           String.starts_with?(name, hint),
           mod = String.to_atom(full_name),
-          struct?(mod) and not function_exported?(mod, :exception, 1),
+          do: {mod, name}
+
+    all = aliases ++ modules
+    Code.ensure_all_loaded(Enum.map(all, &elem(&1, 0)))
+
+    refs =
+      for {mod, name} <- all,
+          function_exported?(mod, :__struct__, 1) and not function_exported?(mod, :exception, 1),
           do: %{kind: :struct, name: name}
 
-    format_expansion(aliases ++ modules, hint)
-  end
-
-  defp struct?(mod) do
-    Code.ensure_loaded?(mod) and function_exported?(mod, :__struct__, 1)
+    format_expansion(refs, hint)
   end
 
   defp expand_container_context(code, context, hint, shell) do
@@ -420,7 +422,9 @@ defmodule IEx.Autocomplete do
   defp container_context_struct(cursor, pairs, aliases, shell) do
     with {pairs, [^cursor]} <- Enum.split(pairs, -1),
          alias = value_from_alias(aliases, shell),
-         true <- Keyword.keyword?(pairs) and struct?(alias) do
+         true <-
+           Keyword.keyword?(pairs) and ensure_loaded?(alias) and
+             function_exported?(alias, :__struct__, 1) do
       {:struct, alias, pairs}
     else
       _ -> nil

lib/iex/lib/iex/broker.ex

@@ -85,9 +85,13 @@ defmodule IEx.Broker do
     yes?(IO.gets(:stdio, interrupt))
   end
 
-  defp yes?(string) do
-    is_binary(string) and String.trim(string) in ["", "y", "Y", "yes", "YES", "Yes"]
-  end
+  defp yes?(string) when is_binary(string),
+    do: String.trim(string) in ["", "y", "Y", "yes", "YES", "Yes"]
+
+  defp yes?(charlist) when is_list(charlist),
+    do: yes?(List.to_string(charlist))
+
+  defp yes?(_), do: false
 
   @doc """
   Client requests a takeover.

lib/iex/lib/iex/cli.ex

@@ -6,7 +6,7 @@ defmodule IEx.CLI do
 
   def deprecated do
     if tty_works?() do
-      :user_drv.start([:"tty_sl -c -e", old_tty_args()])
+      :user_drv.start([:"tty_sl -c -e", tty_args()])
     else
       if get_remsh(:init.get_plain_arguments()) do
         IO.puts(
@@ -20,14 +20,10 @@ defmodule IEx.CLI do
       # IEx.Broker is capable of considering all groups under user_drv but
       # when we use :user.start(), we need to explicitly register it instead.
       # If we don't register, pry doesn't work.
-      IEx.start([register: true] ++ options())
+      IEx.start([register: true] ++ options(), {:elixir, :start_cli, []})
     end
   end
 
-  def prompt(_n) do
-    []
-  end
-
   # Check if tty works. If it does not, we fall back to the
   # simple/dumb terminal. This is starting the linked in
   # driver twice, it would be nice and appropriate if we had
@@ -41,7 +37,7 @@ defmodule IEx.CLI do
     end
   end
 
-  defp old_tty_args do
+  defp tty_args do
     if remote = get_remsh(:init.get_plain_arguments()) do
       remote = List.to_atom(append_hostname(remote))
 
@@ -77,7 +73,7 @@ defmodule IEx.CLI do
   end
 
   defp local_start_mfa do
-    {IEx, :start, [options()]}
+    {IEx, :start, [options(), {:elixir, :start_cli, []}]}
   end
 
   def remote_start(parent, ref) do
@@ -93,8 +89,7 @@ defmodule IEx.CLI do
       spawn_link(fn ->
         receive do
           {:begin, ^ref, other} ->
-            {:ok, _} = Application.ensure_all_started(:elixir)
-            System.wait_until_booted()
+            :elixir.start_cli()
             send(other, {:done, ref})
         end
       end)

lib/iex/lib/iex/helpers.ex

@@ -99,7 +99,7 @@ defmodule IEx.Helpers do
       reenable_tasks(config)
 
       force? = Keyword.get(options, :force, false)
-      args = ["--purge-consolidation-path-if-stale", consolidation]
+      args = ["--purge-consolidation-path-if-stale", "--return-errors", consolidation]
       args = if force?, do: ["--force" | args], else: args
 
       {result, _} = Mix.Task.run("compile", args)

lib/iex/lib/iex/introspection.ex

@@ -293,6 +293,7 @@ defmodule IEx.Introspection do
               module.module_info(:exports)
           end
           |> Enum.sort()
+          |> Enum.dedup()
 
         result =
           for {^function, arity} <- exports,

lib/iex/lib/iex/pry.ex

@@ -689,6 +689,8 @@ defmodule IEx.Pry do
     [asts_string, :faint, " #=> ", :reset, inspect(value, options), "\n\n"]
     |> IO.ANSI.format()
     |> IO.write()
+
+    value
   end
 
   defp chunk_pipeline_asts_by_line(asts, %Macro.Env{line: env_line}) do

lib/logger/lib/logger.ex

@@ -210,7 +210,7 @@ defmodule Logger do
         metadata: [:error_code, :file]
 
   Or to configure default handler, for instance, to log into a file with
-  built-in support for log rotation:
+  built-in support for log rotation and compression:
 
       config :logger, :default_handler,
         config: [
@@ -218,9 +218,18 @@ defmodule Logger do
           filesync_repeat_interval: 5000,
           file_check: 5000,
           max_no_bytes: 10_000_000,
-          max_no_files: 5
+          max_no_files: 5,
+          compress_on_rotate: true
         ]
 
+  See [`:logger_std_h`](`:logger_std_h`) for all relevant configuration,
+  including overload protection. Or set `:default_handler` to false to
+  disable the default logging altogether:
+
+      config :logger, :default_handler, false
+
+  How to add new handlers is covered in later sections.
+
   > #### Keywords or maps {: .tip}
   >
   > While Erlang's logger expects `:config` to be a map, Elixir's Logger
@@ -231,14 +240,6 @@ defmodule Logger do
   > When reading the handler configuration using Erlang's APIs,
   > the configuration will always be read (and written) as a map.
 
-  See [`:logger_std_h`](`:logger_std_h`) for all relevant configuration,
-  including overload protection. Or set `:default_handler` to false to
-  disable the default logging altogether:
-
-      config :logger, :default_handler, false
-
-  How to add new handlers is covered in later sections.
-
   ### Compile configuration
 
   The following configuration must be set via config files (such as
@@ -329,16 +330,19 @@ defmodule Logger do
   default handler, but you can use Erlang's [`:logger`](`:logger`) module
   to add other handlers too.
 
-  Erlang/OTP handlers must be listed under your own application. For example,
-  to setup an additional handler that writes to disk:
+  Erlang/OTP handlers must be listed under your own application.
+  For example, to setup an additional handler, so you write to
+  console and file:
 
       config :my_app, :logger, [
-        {:handler, :disk_log, :logger_disk_log_h, %{
+        {:handler, :file_log, :logger_std_h, %{
            config: %{
-             file: 'system.log',
+             file: ~c"system.log",
              filesync_repeat_interval: 5000,
+             file_check: 5000,
              max_no_bytes: 10_000_000,
-             max_no_files: 5
+             max_no_files: 5,
+             compress_on_rotate: true
            },
            formatter: Logger.Formatter.new()
          }}
@@ -355,9 +359,12 @@ defmodule Logger do
   flexibility but they should avoid performing any long running action in
   such handlers, as it may slow down the action being executed considerably.
   At the moment, there is no built-in overload protection for Erlang handlers,
-  so it is your responsibility to implement it. Alternatively, you can use the
-  [`:logger_backends`](https://github.com/elixir-lang/logger_backends)
-  project.
+  so it is your responsibility to implement it.
+
+  Alternatively, you can use the
+  [`:logger_backends`](https://github.com/elixir-lang/logger_backends) project.
+  It sets up a log handler with overload protection and allows incoming events
+  to be dispatched to multiple backends.
 
   ## Backends and backwards compatibility
 
@@ -824,9 +831,12 @@ defmodule Logger do
 
   defp update_translators(updater) do
     :elixir_config.serial(fn ->
+      translators = updater.(Application.fetch_env!(:logger, :translators))
+      Application.put_env(:logger, :translators, translators)
+
       with %{filters: filters} <- :logger.get_primary_config(),
            {{_, {fun, config}}, filters} <- List.keytake(filters, :logger_translator, 0) do
-        config = update_in(config.translators, updater)
+        config = %{config | translators: translators}
         :ok = :logger.set_primary_config(:filters, filters ++ [logger_translator: {fun, config}])
       end
     end)
@@ -1002,7 +1012,7 @@ defmodule Logger do
       compile_time_purge_matching?(compile_level, compile_metadata) ->
         no_log(data, quoted_metadata)
 
-      Application.fetch_env!(:logger, :always_evaluate_messages) ->
+      Application.get_env(:logger, :always_evaluate_messages, false) ->
         quote do
           data = Logger.__evaluate_log__(unquote(data))
           metadata = unquote(quoted_metadata)
@@ -1110,7 +1120,7 @@ defmodule Logger do
   end
 
   defp no_log(data, metadata) do
-    if Application.fetch_env!(:logger, :always_evaluate_messages) do
+    if Application.get_env(:logger, :always_evaluate_messages, false) do
       quote do
         Logger.__evaluate_log__(unquote(data))
         unquote(metadata)

lib/logger/lib/logger/formatter.ex

@@ -203,7 +203,7 @@ defmodule Logger.Formatter do
 
   def format(_event, _config) do
     raise "invalid configuration for Logger.Formatter. " <>
-            "Use Logger.Formatter.init/1 to define a formatter"
+            "Use Logger.Formatter.new/1 to define a formatter"
   end
 
   defp compute_meta(:module, %{mfa: {mod, _, _}}), do: mod
@@ -498,8 +498,6 @@ defmodule Logger.Formatter do
     rest
   end
 
-  defp metadata(:file, file) when is_list(file), do: file
-
   defp metadata(:domain, [head | tail]) when is_atom(head) do
     Enum.map_intersperse([head | tail], ?., &Atom.to_string/1)
   end
@@ -514,6 +512,8 @@ defmodule Logger.Formatter do
     Exception.format_mfa(mod, fun, arity)
   end
 
+  defp metadata(:function, function) when is_list(function), do: function
+  defp metadata(:file, file) when is_list(file), do: file
   defp metadata(_, list) when is_list(list), do: nil
 
   defp metadata(_, other) do

lib/logger/test/logger/backends/handler_test.exs

@@ -58,7 +58,9 @@ defmodule Logger.Backends.HandlerTest do
   end
 
   test "add_translator/1 and remove_translator/1 for logger formats" do
+    refute {CustomTranslator, :t} in Application.fetch_env!(:logger, :translators)
     assert Logger.add_translator({CustomTranslator, :t})
+    assert {CustomTranslator, :t} in Application.fetch_env!(:logger, :translators)
 
     assert capture_log(fn ->
              :logger.info(~c"hello: ~p", [:ok])

lib/logger/test/logger/formatter_test.exs

@@ -54,6 +54,28 @@ defmodule Logger.FormatterTest do
     assert format_time(time) == ["12", ?:, "30", ?:, "10", ?., [?0, "10"]]
   end
 
+  describe "log" do
+    test "handles :module and :function" do
+      {_, formatter} =
+        new(
+          format: "\n$time $metadata[$level] $message\n",
+          metadata: [:module, :function, :mfa],
+          colors: [enabled: false]
+        )
+
+      assert %{
+               level: :warn,
+               msg: {:string, "foo"},
+               meta: %{
+                 mfa: {Logger.Formatter, :compile, 1}
+               }
+             }
+             |> format(formatter)
+             |> IO.chardata_to_string() =~
+               "module=Logger.Formatter function=compile/1 mfa=Logger.Formatter.compile/1"
+    end
+  end
+
   describe "compile + format" do
     defmodule CompileMod do
       def format(_level, _msg, _ts, _md) do
@@ -66,7 +88,7 @@ defmodule Logger.FormatterTest do
                ["\n", :time, " ", :metadata, "[", :level, "] ", :message, "\n"]
     end
 
-    test "compile with str" do
+    test "compile with string" do
       assert compile("$level $time $date $metadata $message $node") ==
                Enum.intersperse([:level, :time, :date, :metadata, :message, :node], " ")
 

lib/mix/lib/mix.ex

@@ -600,26 +600,29 @@ defmodule Mix do
   """
   @doc since: "1.15.0"
   def ensure_application!(app) when is_atom(app) do
-    ensure_application!(app, Mix.State.builtin_apps())
+    ensure_application!(app, Mix.State.builtin_apps(), [])
     :ok
   end
 
-  defp ensure_application!(app, builtin_apps) do
+  defp ensure_application!(app, builtin_apps, optional) do
     case builtin_apps do
       %{^app => path} ->
         Code.prepend_path(path, cache: true)
         Application.load(app)
+        optional = List.wrap(Application.spec(app, :optional_applications))
 
         Application.spec(app, :applications)
         |> List.wrap()
-        |> Enum.each(&ensure_application!(&1, builtin_apps))
+        |> Enum.each(&ensure_application!(&1, builtin_apps, optional))
 
       %{} ->
-        Mix.raise(
-          "The application \"#{app}\" could not be found. This may happen if your " <>
-            "Operating System broke Erlang into multiple packages and may be fixed " <>
-            "by installing the missing \"erlang-dev\" and \"erlang-#{app}\" packages"
-        )
+        unless app in optional do
+          Mix.raise(
+            "The application \"#{app}\" could not be found. This may happen if your " <>
+              "Operating System broke Erlang into multiple packages and may be fixed " <>
+              "by installing the missing \"erlang-dev\" and \"erlang-#{app}\" packages"
+          )
+        end
     end
   end
 
@@ -674,6 +677,9 @@ defmodule Mix do
     * `:lockfile` (since v1.14.0) - path to a lockfile to be used as a basis of
       dependency resolution.
 
+    * `:start_applications` (since v1.15.3) - if `true`, ensures that installed app
+      and its dependencies are started after install (Default: `true`)
+
   ## Examples
 
   Installing `:decimal` and `:jason`:
@@ -794,6 +800,7 @@ defmodule Mix do
     config_path = expand_path(opts[:config_path], deps, :config_path, "config/config.exs")
     system_env = Keyword.get(opts, :system_env, [])
     consolidate_protocols? = Keyword.get(opts, :consolidate_protocols, true)
+    start_applications? = Keyword.get(opts, :start_applications, true)
 
     id =
       {deps, config, system_env, consolidate_protocols?}
@@ -893,9 +900,11 @@ defmodule Mix do
             end
           end)
 
-          for %{app: app, opts: opts} <- Mix.Dep.cached(),
-              Keyword.get(opts, :runtime, true) and Keyword.get(opts, :app, true) do
-            Application.ensure_all_started(app)
+          if start_applications? do
+            for %{app: app, opts: opts} <- Mix.Dep.cached(),
+                Keyword.get(opts, :runtime, true) and Keyword.get(opts, :app, true) do
+              Application.ensure_all_started(app)
+            end
           end
 
           Mix.State.put(:installed, id)

lib/mix/lib/mix/app_loader.ex

@@ -136,8 +136,12 @@ defmodule Mix.AppLoader do
   end
 
   # We have processed all apps.
-  defp traverse_apps([], _seen, _deps_children, _builtin_paths, _lib_path) do
-    []
+  defp traverse_apps([], seen, _deps_children, builtin_paths, _lib_path) do
+    # We want to keep erts in the load path but it doesn't require to be loaded.
+    case builtin_paths do
+      %{erts: path} when not is_map_key(seen, :erts) -> [{:erts, path}]
+      %{} -> []
+    end
   end
 
   defp app_children(app) do

lib/mix/lib/mix/compilers/elixir.ex

@@ -1,7 +1,7 @@
 defmodule Mix.Compilers.Elixir do
   @moduledoc false
 
-  @manifest_vsn 19
+  @manifest_vsn 20
   @checkpoint_vsn 2
 
   import Record
@@ -46,6 +46,11 @@ defmodule Mix.Compilers.Elixir do
     {all_modules, all_sources, all_local_exports, old_parents, old_cache_key, old_deps_config} =
       parse_manifest(manifest, dest)
 
+    # Prepend ourselves early because of __mix_recompile__? checks
+    # and also that, in case of nothing compiled, we already need
+    # ourselves available in the path.
+    Code.prepend_path(dest)
+
     # If modules have been added or removed from the Erlang compiler,
     # we need to recompile all references to old and new modules.
     stale =
@@ -56,7 +61,7 @@ defmodule Mix.Compilers.Elixir do
         []
       end
 
-    local_deps = Enum.reject(Mix.Dep.cached(), & &1.scm.fetchable?)
+    local_deps = Enum.reject(Mix.Dep.cached(), & &1.scm.fetchable?())
 
     # If mix.exs has changed, recompile anything that calls Mix.Project.
     stale =
@@ -393,7 +398,7 @@ defmodule Mix.Compilers.Elixir do
             Enum.any?(modules, &Map.has_key?(modules_to_recompile, &1)) or
             Enum.any?(external, &stale_external?(&1, modified, sources_stats)) or
             (last_mtime > modified and
-               (missing_beam_file?(dest, modules) or digest != digest_file!(source))),
+               (missing_beam_file?(dest, modules) or digest_changed?(source, digest))),
           do: source
 
     changed = new_paths ++ changed
@@ -423,7 +428,7 @@ defmodule Mix.Compilers.Elixir do
   defp stale_external?({external, digest}, modified, sources_stats) do
     case sources_stats do
       %{^external => {0, 0}} -> digest != nil
-      %{^external => {mtime, _}} -> mtime > modified and digest != digest_file!(external)
+      %{^external => {mtime, _}} -> mtime > modified and digest_changed?(external, digest)
     end
   end
 
@@ -437,8 +442,11 @@ defmodule Mix.Compilers.Elixir do
     end)
   end
 
-  defp digest_file!(file) do
-    file |> File.read!() |> digest_contents()
+  defp digest_changed?(file, digest) do
+    case File.read(file) do
+      {:ok, binary} -> digest != digest_contents(binary)
+      {:error, _} -> true
+    end
   end
 
   defp digest_contents(contents) do
@@ -446,6 +454,9 @@ defmodule Mix.Compilers.Elixir do
       8 -> :crypto.hash(:blake2b, contents)
       _ -> :crypto.hash(:blake2s, contents)
     end
+  rescue
+    # Blake may not be available on all OpenSSL distribution
+    _ -> :erlang.md5(contents)
   end
 
   defp set_compiler_opts(opts) do
@@ -558,18 +569,18 @@ defmodule Mix.Compilers.Elixir do
     Enum.any?(enumerable, &Map.has_key?(map, &1))
   end
 
-  defp stale_local_deps(local_deps, manifest, stale_modules, modified, old_exports) do
+  defp stale_local_deps(local_deps, manifest, stale_modules, modified, deps_exports) do
     base = Path.basename(manifest)
 
     # The stale modules so far will become both stale_modules and stale_exports,
     # as any export from a dependency needs to be recompiled.
     stale_modules = Map.from_keys(stale_modules, true)
 
-    for %{opts: opts} <- local_deps,
+    for %{app: app, opts: opts} <- local_deps,
         manifest = Path.join([opts[:build], ".mix", base]),
         Mix.Utils.last_modified(manifest) > modified,
-        reduce: {stale_modules, stale_modules, old_exports} do
-      {modules, exports, new_exports} ->
+        reduce: {stale_modules, stale_modules, deps_exports} do
+      {modules, exports, deps_exports} ->
         {manifest_modules, manifest_sources} = read_manifest(manifest)
 
         dep_modules =
@@ -584,9 +595,11 @@ defmodule Mix.Compilers.Elixir do
         {dep_modules, _, _} =
           fixpoint_runtime_modules(manifest_sources, Map.from_keys(dep_modules, true))
 
+        old_exports = Map.get(deps_exports, app, %{})
+
         # Update exports
         {exports, new_exports} =
-          for {module, _} <- dep_modules, reduce: {exports, new_exports} do
+          for {module, _} <- dep_modules, reduce: {exports, []} do
             {exports, new_exports} ->
               export = exports_md5(module, false)
 
@@ -600,17 +613,27 @@ defmodule Mix.Compilers.Elixir do
                   do: exports,
                   else: Map.put(exports, module, true)
 
-              # In any case, we always store it as the most update export
-              # that we have, otherwise we delete it.
+              # Then we store the new export if any
               new_exports =
                 if export,
-                  do: Map.put(new_exports, module, export),
-                  else: Map.delete(new_exports, module)
+                  do: [{module, export} | new_exports],
+                  else: new_exports
 
               {exports, new_exports}
           end
 
-        {Map.merge(modules, dep_modules), exports, new_exports}
+        new_exports = Map.new(new_exports)
+
+        removed =
+          for {module, _} <- old_exports,
+              not is_map_key(new_exports, module),
+              do: {module, true},
+              into: %{}
+
+        modules = modules |> Map.merge(dep_modules) |> Map.merge(removed)
+        exports = Map.merge(exports, removed)
+        deps_exports = Map.put(deps_exports, app, new_exports)
+        {modules, exports, deps_exports}
     end
   end
 
@@ -1081,7 +1104,7 @@ defmodule Mix.Compilers.Elixir do
       source(
         source,
         # We preserve the digest if the file is recompiled but not changed
-        digest: source(source, :digest) || digest_file!(file),
+        digest: source(source, :digest) || file |> File.read!() |> digest_contents(),
         compile_references: compile_references,
         export_references: export_references,
         runtime_references: runtime_references,

lib/mix/lib/mix/compilers/erlang.ex

@@ -4,13 +4,13 @@ defmodule Mix.Compilers.Erlang do
   @manifest_vsn 1
 
   @doc """
-  Compiles the files in `mappings` with given extensions into
-  the destination, automatically invoking the callback for each
-  stale input and output pair (or for all if `force` is `true`) and
-  removing files that no longer have a source, while keeping the
-  `manifest` up to date.
+  Compiles the given `mappings`.
 
-  `mappings` should be a list of tuples in the form of `{src, dest}` paths.
+  `mappings` is a list of `{src, dest}` pairs, where the source
+  extensions are compiled into the destination extension,
+  automatically invoking the callback for each stale pair (or for
+  all if `force` is `true`) and removing files that no longer have
+  a source, while keeping the `manifest` up to date.
 
   ## Options
 
@@ -18,6 +18,9 @@ defmodule Mix.Compilers.Erlang do
 
     * `:parallel` - a mapset of files to compile in parallel
 
+    * `:preload` - any code that must be preloaded if any pending
+      entry needs to be compiled
+
   ## Examples
 
   For example, a simple compiler for Lisp Flavored Erlang
@@ -54,22 +57,25 @@ defmodule Mix.Compilers.Erlang do
   def compile(manifest, mappings, src_ext, dest_ext, opts, callback) when is_list(opts) do
     force = opts[:force]
 
-    files =
+    entries =
       for {src, dest} <- mappings,
-          target <- extract_targets(src, src_ext, dest, dest_ext, force),
+          target <- extract_entries(src, src_ext, dest, dest_ext, force),
           do: target
 
-    compile(manifest, files, src_ext, opts, callback)
+    if preload = entries != [] && opts[:preload] do
+      preload.()
+    end
+
+    compile(manifest, entries, src_ext, opts, callback)
   end
 
   @doc """
-  Compiles the given `mappings`.
+  Compiles the given `entries`.
 
-  `mappings` should be a list of tuples in the form of `{src, dest}`.
+  `entries` are a list of `{:ok | :stale, src, dest}` tuples.
 
-  A `manifest` file and a `callback` to be invoked for each src/dest pair
-  must be given. A src/dest pair where destination is `nil` is considered
-  to be up to date and won't be (re-)compiled.
+  A `manifest` file and a `callback` to be invoked for each stale
+  src/dest pair must also be given.
 
   ## Options
 
@@ -78,8 +84,8 @@ defmodule Mix.Compilers.Erlang do
     * `:parallel` - a mapset of files to compile in parallel
 
   """
-  def compile(manifest, mappings, opts \\ [], callback) do
-    compile(manifest, mappings, :erl, opts, callback)
+  def compile(manifest, entries, opts \\ [], callback) do
+    compile(manifest, entries, :erl, opts, callback)
   end
 
   defp compile(manifest, mappings, ext, opts, callback) do
@@ -102,7 +108,7 @@ defmodule Mix.Compilers.Erlang do
     # Clear stale and removed files from manifest
     entries =
       Enum.reject(entries, fn {dest, _warnings} ->
-        dest in removed || Enum.any?(stale, fn {_, stale_dest} -> dest == stale_dest end)
+        dest in removed || List.keymember?(stale, dest, 1)
       end)
 
     if Keyword.get(opts, :all_warnings, true), do: show_warnings(entries)
@@ -156,9 +162,8 @@ defmodule Mix.Compilers.Erlang do
     end
   end
 
-  @doc """
-  Ensures the native OTP application is available.
-  """
+  # TODO: Deprecate this in favor of `Mix.ensure_application!/1` in Elixir v1.19.
+  @doc false
   def ensure_application!(app, _input) do
     Mix.ensure_application!(app)
     {:ok, _} = Application.ensure_all_started(app)
@@ -202,7 +207,7 @@ defmodule Mix.Compilers.Erlang do
     manifest |> read_manifest() |> Enum.map(&elem(&1, 0))
   end
 
-  defp extract_targets(src_dir, src_ext, dest_dir, dest_ext, force) do
+  defp extract_entries(src_dir, src_ext, dest_dir, dest_ext, force) do
     files = Mix.Utils.extract_files(List.wrap(src_dir), List.wrap(src_ext))
 
     for file <- files do

lib/mix/lib/mix/dep.ex

@@ -114,12 +114,12 @@ defmodule Mix.Dep do
         write_cached_deps(top, {env, target}, load_and_cache(config, top, bottom, env, target))
 
       _ ->
-        converge(env: env, target: target)
+        converge_and_load(env: env, target: target)
     end
   end
 
   defp load_and_cache(_config, top, top, env, target) do
-    converge(env: env, target: target)
+    converge_and_load(env: env, target: target)
   end
 
   defp load_and_cache(config, _top, bottom, _env, _target) do
@@ -152,6 +152,20 @@ defmodule Mix.Dep do
     end)
   end
 
+  defp converge_and_load(opts) do
+    for %{app: app, opts: opts} = dep <- Mix.Dep.Converger.converge(opts) do
+      case Keyword.pop(opts, :app_properties) do
+        {nil, _opts} ->
+          dep
+
+        {app_properties, opts} ->
+          # We don't raise because child dependencies may be missing if manually cleaned
+          :application.load({:application, app, app_properties})
+          %{dep | opts: opts}
+      end
+    end
+  end
+
   defp read_cached_deps(project, env_target) do
     case Mix.State.read_cache({:cached_deps, project}) do
       {^env_target, deps} -> deps
@@ -164,6 +178,13 @@ defmodule Mix.Dep do
     deps
   end
 
+  @doc """
+  Although private API, this is kept to avoid breaking code on patch releases.
+  """
+  def load_on_environment(opts) do
+    Mix.Dep.Converger.converge(opts)
+  end
+
   @doc """
   Clears loaded dependencies from the cache for the current environment.
   """
@@ -174,25 +195,6 @@ defmodule Mix.Dep do
     end
   end
 
-  @doc """
-  Returns loaded dependencies recursively on the given environment.
-
-  If no environment is passed, dependencies are loaded across all
-  environments. The result is not cached.
-
-  ## Exceptions
-
-  This function raises an exception if any of the dependencies
-  provided in the project are in the wrong format.
-  """
-  def load_on_environment(opts) do
-    converge(opts)
-  end
-
-  defp converge(opts) do
-    Mix.Dep.Converger.converge(nil, nil, opts, &{&1, &2, &3}) |> elem(0)
-  end
-
   @doc """
   Filters the given dependencies by name.
 

lib/mix/lib/mix/dep/converger.ex

@@ -60,6 +60,18 @@ defmodule Mix.Dep.Converger do
     )
   end
 
+  @doc """
+  Converge without lock and accumulator updates.
+
+  Note the dependencies returned from converge are not yet loaded.
+  The relevant app keys are found under `dep.opts[:app_properties]`.
+
+  See `Mix.Dep.Loader.children/1` for options.
+  """
+  def converge(opts \\ []) do
+    converge(nil, nil, opts, &{&1, &2, &3}) |> elem(0)
+  end
+
   @doc """
   Converges all dependencies from the current project,
   including nested dependencies.
@@ -68,11 +80,14 @@ defmodule Mix.Dep.Converger do
   must return an updated dependency in case some processing
   is done.
 
+  Note the dependencies returned from converge are not yet loaded.
+  The relevant app keys are found under `dep.opts[:app_properties]`.
+
   See `Mix.Dep.Loader.children/1` for options.
   """
   def converge(acc, lock, opts, callback) do
     {deps, acc, lock} = all(acc, lock, opts, callback)
-    if remote = Mix.RemoteConverger.get(), do: remote.post_converge
+    if remote = Mix.RemoteConverger.get(), do: remote.post_converge()
     {topological_sort(deps), acc, lock}
   end
 
@@ -205,21 +220,20 @@ defmodule Mix.Dep.Converger do
         all(t, [dep | acc], upper, breadths, optional, rest, lock, state)
 
       :nomatch ->
-        {%{app: app, deps: deps, opts: opts} = dep, app_properties, rest, lock} =
+        {%{app: app, deps: deps, opts: opts} = dep, rest, lock} =
           case state.cache.(dep) do
             {:loaded, cached_dep} ->
-              {cached_dep, nil, rest, lock}
+              {cached_dep, rest, lock}
 
             {:unloaded, dep, children} ->
               {dep, rest, lock} = state.callback.(put_lock(dep, lock), rest, lock)
 
-              Mix.Dep.Loader.with_system_env(dep, fn ->
-                # After we invoke the callback (which may actually check out the
-                # dependency), we load the dependency including its latest info
-                # and children information.
-                {dep, app_properties} = Mix.Dep.Loader.load(dep, children, state.locked?)
-                {dep, app_properties, rest, lock}
-              end)
+              dep =
+                Mix.Dep.Loader.with_system_env(dep, fn ->
+                  Mix.Dep.Loader.load(dep, children, state.locked?)
+                end)
+
+              {dep, rest, lock}
           end
 
         # Something that we previously ruled out as an optional dependency is
@@ -234,24 +248,7 @@ defmodule Mix.Dep.Converger do
           split_non_fulfilled_optional(deps, Enum.map(acc, & &1.app), opts[:from_umbrella])
 
         new_breadths = Enum.map(deps, & &1.app) ++ breadths
-        res = all(deps, acc, breadths, new_breadths, discarded ++ optional, rest, lock, state)
-
-        # After we traverse all of our children, we can load ourselves.
-        # This is important in case of included application.
-        if app_properties do
-          case :application.load({:application, app, app_properties}) do
-            :ok ->
-              :ok
-
-            {:error, {:already_loaded, _}} ->
-              :ok
-
-            {:error, error} ->
-              Mix.raise("Could not start application #{inspect(app)}: #{inspect(error)}")
-          end
-        end
-
-        res
+        all(deps, acc, breadths, new_breadths, discarded ++ optional, rest, lock, state)
     end
   end
 

lib/mix/lib/mix/dep/loader.ex

@@ -383,21 +383,21 @@ defmodule Mix.Dep.Loader do
 
     cond do
       not ok?(dep) ->
-        {dep, nil}
+        dep
 
       recently_fetched?(dep) ->
-        {%{dep | status: :compile}, nil}
+        %{dep | status: :compile}
 
       opts_app == false ->
-        {dep, nil}
+        dep
 
       true ->
         path = if is_binary(opts_app), do: opts_app, else: "ebin/#{app}.app"
         path = Path.expand(path, opts[:build])
 
         case app_status(path, app, req) do
-          {:ok, vsn, app} -> {%{dep | status: {:ok, vsn}}, app}
-          status -> {%{dep | status: status}, nil}
+          {:ok, vsn, app} -> %{dep | status: {:ok, vsn}, opts: [app_properties: app] ++ opts}
+          status -> %{dep | status: status}
         end
     end
   end

lib/mix/lib/mix/dep/umbrella.ex

@@ -59,7 +59,7 @@ defmodule Mix.Dep.Umbrella do
     apps = Enum.map(deps, & &1.app)
 
     Enum.map(deps, fn umbrella_dep ->
-      {umbrella_dep, _} = Mix.Dep.Loader.load(umbrella_dep, nil, false)
+      umbrella_dep = Mix.Dep.Loader.load(umbrella_dep, nil, false)
 
       deps =
         Enum.filter(umbrella_dep.deps, fn dep ->

lib/mix/lib/mix/release.ex

@@ -67,7 +67,7 @@ defmodule Mix.Release do
   @default_apps [kernel: :permanent, stdlib: :permanent, elixir: :permanent, sasl: :permanent]
   @safe_modes [:permanent, :temporary, :transient]
   @unsafe_modes [:load, :none]
-  @significant_chunks ~w(Atom AtU8 Attr Code StrT ImpT ExpT FunT LitT Line)c
+  @additional_chunks ~w(Attr)c
   @copy_app_dirs ["priv"]
 
   @doc false
@@ -285,7 +285,8 @@ defmodule Mix.Release do
               |> Enum.map(&{&1, new_mode})
 
             seen = put_in(seen[app][:mode], new_mode)
-            load_apps(apps, deps_apps, seen, otp_root, [], overrides)
+            optional = Keyword.get(properties, :optional_applications, [])
+            load_apps(apps, deps_apps, seen, otp_root, optional, overrides)
 
           true ->
             seen
@@ -878,7 +879,7 @@ defmodule Mix.Release do
   @spec strip_beam(binary(), keyword()) :: {:ok, binary()} | {:error, :beam_lib, term()}
   def strip_beam(binary, options \\ []) when is_list(options) do
     chunks_to_keep = options[:keep] |> List.wrap() |> Enum.map(&String.to_charlist/1)
-    all_chunks = Enum.uniq(@significant_chunks ++ chunks_to_keep)
+    all_chunks = Enum.uniq(@additional_chunks ++ :beam_lib.significant_chunks() ++ chunks_to_keep)
     compress? = Keyword.get(options, :compress, false)
 
     case :beam_lib.chunks(binary, all_chunks, [:allow_missing_chunks]) do

lib/mix/lib/mix/task.ex

@@ -58,14 +58,22 @@ defmodule Mix.Task do
 
       @requirements ["app.config"]
 
-  Tasks typically depend on the `"app.config"` task, when they
-  need to access code from the current project with all apps
-  already configured, or the "app.start" task, when they also
-  need those apps to be already started:
+  A task will typically depend on one of the following tasks:
 
-      @requirements ["app.start"]
+    * "loadpaths" - this ensures dependencies are available
+      and compiled. If you are publishing a task as part of
+      a library to be used by others, and your task does not
+      need to interact with the user code in any way, this is
+      the recommended requirement
 
-  You can also run tasks directly with `run/2`.
+    * "app.config" - additionally compiles and loads the runtime
+      configuration for the current project. If you are creating
+      a task to be used within your application or as part of a
+      library, which must invoke or interact with the user code,
+      this is the minimum recommended requirement
+
+    * "app.start" - additionally starts the supervision tree of
+      the current project and its dependencies
 
   Finally, set `@recursive true` if you want the task to run
   on each umbrella child in an umbrella project.

lib/mix/lib/mix/tasks/archive.build.ex

@@ -61,7 +61,7 @@ defmodule Mix.Tasks.Archive.Build do
     project = Mix.Project.get()
 
     if project && Keyword.get(opts, :compile, true) do
-      Mix.Task.run(:compile, args)
+      Mix.Task.run(:compile, ["--no-protocol-consolidation" | args])
     end
 
     source =

lib/mix/lib/mix/tasks/compile.all.ex

@@ -31,7 +31,7 @@ defmodule Mix.Tasks.Compile.All do
     {loaded_paths, loaded_modules} =
       Mix.AppLoader.load_apps(apps, deps, config, {[], []}, fn {app, path}, {paths, mods} ->
         paths = if path, do: [path | paths], else: paths
-        mods = if app_cache, do: [{app, Application.spec(app, :modules)} | mods], else: mods
+        mods = if app_cache, do: [{app, Application.spec(app, :modules) || []} | mods], else: mods
         {paths, mods}
       end)
 
@@ -43,7 +43,11 @@ defmodule Mix.Tasks.Compile.All do
       Code.delete_paths(current_paths -- loaded_paths)
     end
 
-    Code.prepend_paths(loaded_paths -- current_paths, cache: true)
+    # Add the current compilation path. compile.elixir and compile.erlang
+    # will also add this path, but only if they run, so we always add it
+    # here too. Furthermore, we don't cache it as we may still write to it.
+    compile_path = to_charlist(Mix.Project.compile_path())
+    Code.prepend_paths([compile_path | loaded_paths -- current_paths], cache: true)
 
     result =
       if "--no-compile" in args do
@@ -64,12 +68,6 @@ defmodule Mix.Tasks.Compile.All do
       Mix.AppLoader.write_cache(app_cache, Map.new(loaded_modules))
     end
 
-    # Add the current compilation path. compile.elixir and compile.erlang
-    # will also add this path, but only if they run, so we always add it
-    # here too. Furthermore, we don't cache it as we may still write to it.
-    compile_path = to_charlist(Mix.Project.compile_path())
-    _ = Code.prepend_path(compile_path)
-
     unless "--no-app-loading" in args do
       app = config[:app]
 
@@ -125,7 +123,7 @@ defmodule Mix.Tasks.Compile.All do
     Enum.reduce(Mix.ProjectStack.pop_after_compiler(compiler), result, & &1.(&2))
   end
 
-  defp project_apps(config) do
+  def project_apps(config) do
     project = Mix.Project.get!()
 
     properties =

lib/mix/lib/mix/tasks/compile.ex

@@ -146,10 +146,9 @@ defmodule Mix.Tasks.Compile do
     config = Mix.Project.config()
 
     # If we are in an umbrella project, now load paths from all children.
-    if Mix.Project.umbrella?(config) do
+    if apps_paths = Mix.Project.apps_paths(config) do
       loaded_paths =
-        Mix.Project.apps_paths(config)
-        |> Map.keys()
+        (Mix.Tasks.Compile.All.project_apps(config) ++ Map.keys(apps_paths))
         |> Mix.AppLoader.load_apps(Mix.Dep.cached(), config, [], fn
           {_app, path}, acc -> if path, do: [path | acc], else: acc
         end)

lib/mix/lib/mix/tasks/compile.leex.ex

@@ -53,15 +53,19 @@ defmodule Mix.Tasks.Compile.Leex do
       Mix.raise(":leex_options should be a list of options, got: #{inspect(options)}")
     end
 
-    opts = [parallel: true] ++ opts
+    opts = [parallel: true, preload: &preload/0] ++ opts
 
     Erlang.compile(manifest(), mappings, :xrl, :erl, opts, fn input, output ->
-      Erlang.ensure_application!(:parsetools, input)
       options = options ++ @forced_opts ++ [scannerfile: Erlang.to_erl_file(output)]
       :leex.file(Erlang.to_erl_file(input), options)
     end)
   end
 
+  defp preload do
+    Mix.ensure_application!(:parsetools)
+    {:ok, _} = Application.ensure_all_started(:parsetools)
+  end
+
   @impl true
   def manifests, do: [manifest()]
   defp manifest, do: Path.join(Mix.Project.manifest_path(), @manifest)

lib/mix/lib/mix/tasks/compile.yecc.ex

@@ -53,15 +53,19 @@ defmodule Mix.Tasks.Compile.Yecc do
       Mix.raise(":yecc_options should be a list of options, got: #{inspect(options)}")
     end
 
-    opts = [parallel: true] ++ opts
+    opts = [parallel: true, preload: &preload/0] ++ opts
 
     Erlang.compile(manifest(), mappings, :yrl, :erl, opts, fn input, output ->
-      Erlang.ensure_application!(:parsetools, input)
       options = options ++ @forced_opts ++ [parserfile: Erlang.to_erl_file(output)]
       :yecc.file(Erlang.to_erl_file(input), options)
     end)
   end
 
+  defp preload do
+    Mix.ensure_application!(:parsetools)
+    {:ok, _} = Application.ensure_all_started(:parsetools)
+  end
+
   @impl true
   def manifests, do: [manifest()]
   defp manifest, do: Path.join(Mix.Project.manifest_path(), @manifest)

lib/mix/lib/mix/tasks/deps.clean.ex

@@ -41,7 +41,7 @@ defmodule Mix.Tasks.Deps.Clean do
           value = opts[switch],
           do: {key, :"#{value}"}
 
-    loaded_deps = Mix.Dep.load_on_environment(loaded_opts)
+    loaded_deps = Mix.Dep.Converger.converge(loaded_opts)
 
     apps_to_clean =
       cond do