Update: Darn - it's back. Completely ignore the below meditation, instead to post a question!

This is a rehash of a stack-overflow answer I just made. I hope that's not against modern Perlmonks etiquette!

I recently got an odd error in some code that definitely worked before:

Google told me only that someone had seen the same error in a cgi once.

How I fixed it might be instructive although I'm still not exactly sure what it means. The code, that worked in some calling circumstances but not others, was a simple method forwarding method that looked a little like this:

sub quick_method {
    return shift->SUPER::some_other_method(@_);
}
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It's a little lazy, sure, but according to perl's left to right evaluation, it should (and usually was) the equivalent of this:

sub quick_method {
    my $self = shift;
    my @args = @_;
    return $self->SUPER::some_other_method(@args);
}
[download]

I'm guessing that since @_ is, under some circumstances, a special way of accessing the stack and, under other circumstances, a fairly regular global list, the way in which the method was called was hitting different code paths.

Moral of the story - don't get too cute about modifying and using @_ in the same line of code!