The JRuby community is pleased to announce the release of JRuby 9.4.13.0.

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

JRuby 9.4.13.x targets Ruby 3.1 compatibility.

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

Stability

• Fixed a slow memory leak in subclass management. (#8842, #8844)
• Fixed a potential deadlock during multi-threaded boot and concurrent JIT compilation. (#8845, #8849)

Usability

• Backported JRuby .sh launcher features from JRuby 10, including AppCDS flags for improved startup time. (#8565, #8625, #8626, #8652, #8653, #8656, #8754)

56 Issues and PRs resolved for 9.4.13.0

• #8351 Zlib::GzipReader missing each_char iterator
• #8426 Dir[] vs "../../"
• #8506 Test new version of resolv
• #8526 obj.first caused Java::JavaUtil::NoSuchElementException on an empty Java21 ArrayList
• #8542 Fix Dir.glob ../ and cases
• #8565 JRuby native launcher seems to get confused when both --dev and -Xcompile.mode=JIT are applied
• #8574 Improvements to support json library
• #8577 ArgumentError: unknown keyword for required keyword argument
• #8599 Fixes #8577. kwargs checking: Use bits instead of index
• #8608 add zlib each_char
• #8611 Setting an instance var on a Java object no longer warns
• #8613 Warn when creating a new ivar table on JavaProxy wrapper
• #8623 Installing sassc broke on jruby-head on Windows
• #8625 Add --cache flag to regenerate AppCDS
• #8626 Fix default arguments for generating AppCDS flag
• #8635 Fix tr! and reverse! on ByteList view with non-zero begin index
• #8643 Fixes to get stringio tests and specs green
• #8645 Update stringio to 3.1.5
• #8648 Handle errors whe looking for Java executable
• #8652 Use set -u to avoid accessing uninitialized variables
• #8653 Align 9.4 launcher with 10
• #8654 fix glob dir on windows
• #8655 Make some private helpers for glob
• #8656 Additional fixes for jruby.sh
• #8661 Update Unicode to 15.0
• #8663 copy-rename-maven-plugin version
• #8667 Update jcodings to 1.0.62 and joni to 2.2.4
• #8671 fix a regression in KDDI transcoding
• #8681 Update MRI core tests and tag failures
• #8686 rbByteEncode fails to no-op when encodings are the same
• #8687 Handle encoding checks as in strTranscode
• #8688 Tracing :call with TracePoint (and --debug flag) makes kwargs unusable
• #8691 Implement AutoCloseable on JRubyEngine
• #8692 Save original callers callInfo in tracepoint
• #8696 New restriction warnings on Java 24
• #8715 Fix missing 2 arg for IO#readline
• #8728 Incorrect warning: given block not used
• #8731 [ji] avoid false duplicate method warning
• #8733 Remove this warning to match standard set.rb
• #8754 Backport jruby.sh from JRuby 10
• #8755 Update uri to version 0.12.3 in JRuby 9.4
• #8789 Dir.glob and Dir[] on existing file URL raises error
• #8795 Possible typo in lib/ruby/stdlib/jruby/compiler.rb:61
• #8805 Possible NPE in RubyModule:searchWithCacheMiss() found by SAST
• #8806 Possible NPE in StringSupport:rbStrEnumerateLines() found by SAST
• #8820 Fix recent potential NPE reports
• #8821 Always cache undef along these paths
• #8825 Update net-imap from 0.2.3 to 0.2.5
• #8827 Update to net-imap 0.2.5 for security fixes
• #8830 Splat with multi-line expression improperly expands
• #8834 Missing splatNode creation
• #8842 Metaspace leak in 9.4
• #8844 Use a normal ClassValue for all such cases
• #8845 Fix locking of stable class values for JI proxies
• #8849 Clean up some locking around hierarchy modification
• #8857 Migrate to the new Maven Central publishing system