Tip: given a coderef, show me where the code is

In Perl, sometimes you have a coderef, normally a callback, and you need to know where is that code located in your source.

This will do the trick:

sub _dude_wheres_my_coderef {
    use Devel::Peek;
    $code = \&$code; # guarantee a hard reference
    my $gv = Devel::Peek::CvGV ($code) or return;
    return *$gv{PACKAGE} . '::' . *$gv{NAME};
}

Taken from dump_vars.pl. BTW, $name also includes filename and line number.