Issues

Issues

• Hash#merge, #merge! and #update pass one Array to the block instead of three values

  jruby/jruby#10053 · opened on Nov 12, 2026

• Mod::X ||= value assigns nothing when a top-level constant X exists

  jruby/jruby#10051 · opened on Nov 12, 2026

• case/when skips all but the last statement of a parenthesized when value

  jruby/jruby#10049 · opened on Nov 12, 2026

• Proposal: generate ri docs with JRuby's rdoc at release time instead of downloading Debian's package

  jruby/jruby#10039 · opened on Nov 11, 2026

• Pin Bouncy Castle versions in JRuby's build to avoid range resolution in CI

  jruby/jruby#10038 · opened on Nov 11, 2026
  3

• ARGF.getc and ARGF.readchar return byte Integers instead of one-character Strings

  jruby/jruby#10032 · opened on Nov 11, 2026

• Race condition between ENV modification and backticks causes array out of bounds exception

  jruby/jruby#10031 · opened on Nov 10, 2026

• Queue#pop(timeout:) and SizedQueue#push(timeout:) receive Thread#kill / Thread#raise inside Thread.handle_interrupt(Object => :never)

  jruby/jruby#10028 · opened on Nov 10, 2026

• Backport fiber scheduler blocking hooks (Kernel#sleep, Mutex, ConditionVariable, Queue) to 10.0.x

  jruby/jruby#10027 · opened on Nov 10, 2026

• 10.1.3.0: keyword-argument call inside a (...) method raises ArgumentError

  jruby/jruby#10026 · opened on Nov 10, 2026

• pack/unpack when the string, format or buffer changes during the call

  jruby/jruby#10022 · opened on Nov 10, 2026

• Rails 8.2 incompatible with JRuby

  jruby/jruby#10020 · opened on Nov 8, 2026
  1

• Time.at(t, in: nil) returns UTC instead of the local time (or the time zone of t), unlike CRuby

  jruby/jruby#10018 · opened on Nov 8, 2026

• Time.new reads an offset of -0000 or -00 as +00:00 rather than UTC, unlike CRuby, and so does Time.iso8601 since 10.1.3.0

  jruby/jruby#10016 · opened on Nov 7, 2026

• Kernel#inspect calls method_missing for instance_variables_to_inspect even when respond_to_missing? is false

  jruby/jruby#10012 · opened on Nov 6, 2026

• -w now warns "method redefined" for JRuby's bundled stdlib (open3/jruby_windows, io/console) since 10.1.3.0

  jruby/jruby#10010 · opened on Nov 5, 2026 · JRuby 10.1.4.0
  1

• Investigate performance of String#tr

  jruby/jruby#9990 · opened on Nov 3, 2026 · JRuby 10.1.4.0
  3

• Concurrent PTY.spawn crashes the JVM in libfixposix

  jruby/jruby#9977 · opened on Nov 2, 2026
  1

• IO#write after a partial write blocks until a thread reading the same socket wakes up

  jruby/jruby#9886 · opened on Oct 26, 2026 · JRuby 10.1.4.0
  4

• Date#to_java(java.sql.Date) gives the day before when the JVM's time zone is west of UTC

  jruby/jruby#9883 · opened on Oct 24, 2026
  2

• File.join transcodes an ASCII-8BIT argument as ISO-8859-1, changing its bytes

  jruby/jruby#9880 · opened on Oct 24, 2026
  3

• IO.copy_stream writes ASCII-8BIT to a non-IO destination, rather than the source's text in its encoding

  jruby/jruby#9881 · opened on Oct 24, 2026
  2

• Backtrace lines can have stale encoding flags for non-ASCII method names and instance_eval file names

  jruby/jruby#9879 · opened on Oct 23, 2026 · JRuby 10.0.x
  3

• Thread#kill on a thread reading a socket closes the socket (EBADF on the next read)

  jruby/jruby#9875 · opened on Oct 22, 2026

• Set up bench dir with JMH project and runner harnesses

  jruby/jruby#9807 · opened on Oct 15, 2026 · Non-Release