Bug #16369: Segfault : crashed on child side of fork pre-exec thread_pool.rb

• Status: Third Party's Issue
• Assignee: -
• Target version: -
• ruby -v: ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin18]
• Backport: 2.5: UNKNOWN, 2.6: UNKNOWN
• Tags: thread

[j15e (Jean-Philippe Doyle)]

It occurs at random in development on my rails 6 app with puma server, so unfortunately I do not have very reproducible steps.

Maybe someone with more knowledge of ruby crash reports could suggest some hints?

[j15e (Jean-Philippe Doyle)]

After a bit more research, I think this might be the same issue as https://bugs.ruby-lang.org/issues/16288#note-2 so feel free to close if that is the case

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Third Party's Issue

This crashes inside the pg gem: https://github.com/ged/ruby-pg/blob/v1.1.4/ext/pg_connection.c#L3221-L3240. My guess is you are not disconnecting before forking and you end up sharing connections between processes, which can easily cause segfaults. Always disconnect database connections before forking if using a forking webserver.

If you can reproduce the example with just the pg gem and without forking, you should try reporting the issue to the pg gem maintainers: https://github.com/ged/ruby-pg/issues