Well said. Even an awesome library with no bugs that has no external dependencies still depends on the stdlib. For a while, before we were using containers, we even had the issue on Mac dev machines especially, where a half dozen Rubygems would crash while building its C extensions if your Mac OS version wasn’t just what the author expected, due to changes in the compiler shipped by Apple. So a MacOS major update might on its own functionally break a gem, even if the gem itself was designed well and you were using the same Ruby version.