As somebody who dosen't poke around in perls internals, my wild guess is that @_ in the "pre"-callback contains a (pointer to a) glob whose object has passed out of existence already, but that's a wild guess obviously.

In a "pre" callback, the last argument is really a reference to a Hook::LexWrap::Cleanup object (a blessed subroutine), which masquerades as undef when used as an rvalue.

When $_[-1] is assigned to in a "pre" callback, this object loses its last reference, so its destructor is called, which invokes the advertised "short-circuiting" of the wrapped subroutine.

Not having (or wanting!) access to a Windows machine, I can only guess that something in LexWrap is tripping a bug in the IndigoPerl core -- possibly something to do with destructor timing. :-(

In reply to Re: Bug ? Perl dumps core on reference to @_ ? by TheDamian
in thread Bug ? Perl dumps core on reference to @_ ? by Corion

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