After upgrading to the 2.12.0 version of the JSON gem (2.11.3 is fine and earlier are fine), we started seeing occasional SIGSEGV's of Ruby itself when calling the to_json on certain Hash's. A co developer was able to capture an example Hash that always causes a core dump.

So to be nice and documented/reproducible,(and the fact the Hash is ugly) I made a repo here with a quick example of a data set with notes in README.md on how to reproduce, as well as other fun data

Overall, Version 2.12.0 shows this issue, versions older than that do not.
I have re-produced this on Ruby 3.3.7 and 3.4.4
On Ubuntu 24.04 and AL2023 (For a Redhat like flavor)

Code, and details on all above can be found in this repo.

https://github.com/matobinder/demo-json-ruby-crash

Seeing as its crashing, its probably a problem in Ruby itself, but I know JSON gem has some C of its own, but not sure if its totally related here