I didn't know about @CARP_NOT, so I learned something new today.

Someone may have to add something after all.

Well, rather than staring for an hour I would have been pragmatic and used pragmas, and caller:

sub err {
    $Carp::CarpLevel = $carplevel;
    if ($which eq 'croak') {
        my @c = $carplevel ? caller($carplevel-1) : (undef,__FILE__,__
+LINE__);
        die "You did something bad! at $c[1] line $c[2]\n";
    } else {
        confess "You did something bad!"; #line 14
    }
}
[download]

and croak/confess carplevels are consistent.

It seems that setting @CARP_NOT makes croak do a confess.

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}