Issue #22442 has been reported by mame (Yusuke Endoh). ---------------------------------------- Bug #22442: Lazy loading of error_highlight etc. is skipped in threads and Ractors https://bugs.ruby-lang.org/issues/22442 * Author: mame (Yusuke Endoh) * Status: Assigned * Assignee: hsbt (Hiroshi SHIBATA) * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- #21951 made error_highlight / did_you_mean / syntax_suggest lazily loaded. When the lazy loading is triggered concurrently from threads or Ractors, the decoration may be skipped. ```ruby # repro.rb rs = 2.times.map do Ractor.new do nil.upcase rescue => e e.detailed_message(highlight: false) end end rs.each { puts it.value, "" } ``` Expected: ``` $ ruby repro.rb undefined method 'upcase' for nil (NoMethodError) nil.upcase ^^^^^^^ undefined method 'upcase' for nil (NoMethodError) nil.upcase ^^^^^^^ ``` Actual: ``` $ ruby repro.rb undefined method 'upcase' for nil (NoMethodError) nil.upcase ^^^^^^^ undefined method 'upcase' for nil (NoMethodError) ``` Cause: the first caller of `detailed_message` sets a flag when it starts loading. So when another thread or Ractor calls it during the load, it returns without decoration instead of waiting for the load to complete. Fix: fire the `autoload` instead of calling `rb_require_string`, so that the autoload's synchronization prevents the skip. https://github.com/ruby/ruby/pull/19352 Also, because `rb_require_string` was used, a newer version installed by `gem install error_highlight` was not used. Firing the `autoload` respects the monkeypatch of `Kernel#require`, so the newer version of error_highlight will be used. Note: this is why the snippet is not shown in #22439. -- https://bugs.ruby-lang.org/