Comment by lucaspiller

I've been in the same situation as OP many times (although in most cases I've been brought in fix someone else's code).

In the Ruby ecosystem, library authors didn't really start caring about semantic versioning and backwards compatability until a few years ago. Even finding a changelog circa 2011 was a godsend.

I think this was mainly caused by the language itself not caring about those either. 10 years ago upgrading between patch releases of Ruby (MRI) was likely to break something.

At least this is one thing JavaScript seems to do better.