They don't get along.
As of the recent 1.07 release,
Perl::Critic, has started using
Readonly to be more more self-compliant with Perl Best Practices. We had been avoiding use of
constant for the reasons described in the book, but had not been willing to add the
Readonly dependency until now.
Perl::Critic coding standard has been to use sigils for subroutines in
@EXPORT_OK, etc. and import lists, but
Exporter treats them as optional. And, in fact, there's code that strips them off (line 47 in v5.58). I haven't figured out the commonality, but in a few environments, this fails spectacularly. Once we removed the subroutine sigils from everywhere, the problems have gone.
Explicitness: 0, Keyboard laziness: 1.