Elixir v1.20.0-rc.4 released!

NewsBot · 31 March 2026 12:22

Elixir v1.20.0-rc.4 has been released.

This release requires Erlang/OTP 27+ and is compatible with Erlang/OTP 29.

1. Enhancements

Elixir

[Code] Add :dbg_callback option to eval functions

[Code.Fragment] Allow preserving sigil metadata in container_cursor_to_quoted

[File] Add support for [:raw] opts in File.read/2

[Kernel] Show undefined function errors even when missing variables (this helps debug errors caused when the developer forgets to require a macro)

[Module] Purge and delete modules if after_verify/2 callback fails

[PartitionSupervisor] Support via tuples in count_children/1 and stop/3

[Process] Add Process.get_label/1

Mix

[mix deps] Allow overriding specific dependencies in :override

2. Bug fixes

Elixir

[Integer] Fix Integer.extended_gcd/2 returning negative GCD for zero base cases

[Integer] Raise when negative out-of-range digits are given to Integer.undigits/2

[Kernel] Protocols should not add compile-time dependencies on Any implementation

[Kernel] Ensure structs trigger recompilation for type checking purposes (regression)

[Kernel] Ensure type information propagate across hd/tl in guards (regression)

[Keyword] Raise ArgumentError in Keyword.from_keys/2 for non-atom keys

[URI] Fix URI.merge leaking :+ marker when base path is empty string

ExUnit

[ExUnit.Diff] Avoid false positives when diffing bitstrings

Mix

[mix deps] Use config files to pass project state to avoid argv limits on Windows when using MIX_OS_DEPS_COMPILE_PARTITION_COUNT

[mix compile] Fix compile env change triggering full recompilation of path dependencies

[mix compile] Add a build lock around protocol consolidation in umbrellas

[mix compile] Ensure compilation of sibling deps do not mark path deps as changed

[mix test] Fix --warnings-as-errors not catching misnamed test file warnings

Link: Release v1.20.0-rc.4 · elixir-lang/elixir · GitHub