See also:

• Release 3.5.0-preview1 · ruby/ruby
• Release 4.0.0-preview2 · ruby/ruby
• Release 4.0.0-preview3 · ruby/ruby

What's Changed

• Bump RDoc to 7.0.1 by st0012 · Pull Request #15628
• make rb_singleton_class ractor safe by luke-gruber · Pull Request #15591
• Remove assertion in encoded_iseq_trace_instrument by luke-gruber · Pull Request #15616
• Bug #21793: function name conflict of "mutex_trylock" on Solaris - Ruby - Ruby Issue Tracking System
• [DOC] small improvements to ractor class docs by luke-gruber · Pull Request #15584
• Check for NULL fields in TYPEDDATA memsize functions by luke-gruber · Pull Request #15633
• Feature #21785: Add signed and unsigned LEB128 support to pack / unpack - Ruby - Ruby Issue Tracking System
• Fix rbs test failure caused by minitest6 by soutaro · Pull Request #15643
• Fix: Do not check open_timeout twice by shioimm · Pull Request #15626
• Fix: Specifying 0 should cause an immediate timeout by shioimm · Pull Request #15641
• Bug #21794: O_CLOEXEC is not available on Solaris 10 - Ruby - Ruby Issue Tracking System
• Fiber scheduler: invoke #io_write hook on IO flush by noteflakes · Pull Request #15609
• Update NEWS.md for Fiber Scheduler by noteflakes · Pull Request #15629
• Small documentation adjustments for new/updated features by zverok · Pull Request #15634
• Add clarifications about the Enumerator.size by zverok · Pull Request #15615
• Bug #21792: 4.0.0-preview3: Build fails with --with-ext= when ENABLE_SHARED=yes: ruby/digest.h not found for rubyspec CAPI extensions - Ruby - Ruby Issue Tracking System
• [DOC] Enhancements for globals.md by BurdetteLamar · Pull Request #15545
• Small improvements to doc/language/ractor.md by luke-gruber · Pull Request #15588
• More doc improvements to ractor.md by luke-gruber · Pull Request #15676
• Bump RDoc to 7.0.2 by st0012 · Pull Request #15691
• [DOC] Improve ractor class docs (grammar, code examples) by luke-gruber · Pull Request #15686
• [DOC] Languages in Examples by BurdetteLamar · Pull Request #15697
• Bundle RBS 3.10.0 by soutaro · Pull Request #15701
• Describe base code layout rules by zverok · Pull Request #15696
• [DOC] Enhance Fiber::Scheduler docs by zverok · Pull Request #15708
• [DOC] Cross-links between Japanese and English pages by BurdetteLamar · Pull Request #15705
• ZJIT: Don't mark control-flow opcodes as invalidating locals by tekknolagi · Pull Request #15694
• [DOC] Add back Rust 1.85.0 requirement to NEWS.md by chancancode · Pull Request #15728

Note: This list is automatically generated by tool/gen-github-release.rb. Because of this, some commits may be missing.

Full Changelog

https://github.com/ruby/ruby/compare/v4.0.0-preview3...v4.0.0