Perl as a language is pretty mature and rarely sees breaking changes (and what breaking changes exist are in corners of the language that are extremely esoteric even for Perl). You can take a Perl script written 25 years ago and it'll still run just fine.
New language features and things that might alter existing behavior are usually locked behind a version declaration opt-in at the top of your script. You need to do something similar to `use v5.39;` to unlock new behaviors from that version of Perl -- which may contain breaking changes but those are also generally backward compatible too.
But that's for the base language and standard library. Individual third-party packages may vary in their backward compatibility.
New language features and things that might alter existing behavior are usually locked behind a version declaration opt-in at the top of your script. You need to do something similar to `use v5.39;` to unlock new behaviors from that version of Perl -- which may contain breaking changes but those are also generally backward compatible too.
But that's for the base language and standard library. Individual third-party packages may vary in their backward compatibility.