Where is the previous version referred to in the codebase? I'm guessing that would be the place to look for changes.

If you can't find an update at that place in the codebase saying 1.4.0 you can ask where it is. It seems after doing that and not receiving an answer would be the appropriate time to start making the claims that people are throwing around.

This seems like a candidate

https://github.com/oven-sh/bun/commit/b18bf6d1d0a92238f240bf...