JRuby Released

Monday, August 03 2020

The JRuby community is pleased to announce the release of JRuby

JRuby 9.2.x is compatible with Ruby 2.5.x and stays in sync with C Ruby. As always there is a mix of miscellaneous fixes so be sure to read the issue list below. All users are encouraged to upgrade.

As we are still actively working on we decided to put out another 9.2.x release to fix some of the more recently reported issues.



  • Internal structures used to optimize Ruby code have been made more thread-safe. Previously, these optimizations could be seen across threads in a partially-complete state, leading to errors in JRuby’s core runtime. (#6319, #6323, #6337)

Ruby Compatibility

  • IO.copy_stream has been fixed to ensure all read bytes are written. Previously, partial writes would leave some read bytes in limbo, leading to hangs in net/http among other libraries. (#6078, #6348)
  • Fixed a regression from in how we translate JDK socket errors to Ruby’s Errno on Windows. (#6322, #6328)


  • FFI has been patched to not automatically release memory pointers when autorelease is disabled. This caused crashes in the sassc native library and possibly others. (#6310, #6331)

  • 12 issues fixed for

Github Issues resolved for

  • #6348 - [fix][backport] Ensure copy_stream write sends all bytes read
  • #6337 - JRuby OpenJDK11 java.lang.ArrayIndexOutOfBoundsException from JRuby Runtime
  • #6332 - Update Psych to 3.2.0
  • #6331 - Allow false autorelease to set unmanaged = true
  • #6328 - Fall back on old regexp BindException mapping
  • #6323 - Eliminate concurrent modification of runtime-sensitive IR state
  • #6322 - Windows raising different exception since
  • #6320 - Update snakeyaml to version 1.26 or higher CVE-2017-18640
  • #6319 - org.jruby.runtime.scopes.DynamicScope6 only supports scopes with 6 variables on JRuby
  • #6310 - Rails: After migration from ruby to jruby, app is not booting
  • #6284 - FFI::MemoryPointer autorelease issue
  • #6078 - net/http hangs (timeouts) since