What output do you get if you enable debugging via the following two environment variables?

(1) for DynaLoader (loading of XS modules, shared libs):

> set PERL_DL_DEBUG=1
> perl zipper.pl
[download]

(2) for execution tracing:

> set PERLDB_OPTS="AutoTrace NonStop"
> perl -ds zipper.pl
[download]

How far does the latter get? Does it terminate permaturely, i.e. what are the last lines executed?

(See perldebug for other options you might want to set with PERLDB_OPTS, e.g. frame=...)