Yes, most of them relatively minor though, which is why the OP has never stumbled across one.
(I found one once-- it turned out one coder had invented his own hash slice syntax. It wasn't supposed to work, but it did, until a particular upgrade...).
In general, Perl has been traditionally committed to backwards compatibility, but not fanatically so-- there is a deprecation cycle that can be used to remove the more problematic things.
Yes, most of them relatively minor though, which is why the OP has never stumbled across one.
(I found one once-- it turned out one coder had invented his own hash slice syntax. It wasn't supposed to work, but it did, until a particular upgrade...).
In general, Perl has been traditionally committed to backwards compatibility, but not fanatically so-- there is a deprecation cycle that can be used to remove the more problematic things.