The JRuby community is pleased to announce the release of JRuby 9.4.12.0.

• Homepage: https://www.jruby.org/
• Download: https://www.jruby.org/download

JRuby 9.4.12.x targets Ruby 3.1 compatibility.

Thank you to our contributors this release, you help keep JRuby moving forward!

Critical Fixes

• Added additional locking to the new Class#subclasses implementation to fix a concurrent modification error. #8602, #8603

Standard Library

• jar-dependencies upgraded to 0.5.4 to fix an issue parsing Maven output on Java versions 9 and higher. #8606, [#8515]

4 Issues and PRs resolved for 9.4.12.0

• #8602 ConcurrentModificationException in subclasses map
• #8603 Ensure subclass set prevents concurrent modification
• #8606 No such file or directory snakeyaml-engine-2.9.jar in JRuby 9.4.11.0
• #8615 Use jar-dependencies 0.5.4