Either add -Mdiagnostics to your program, or grep through the perldiag manpage, and you'll find:

       Insecure dependency in %s
           (F) You tried to do something that the tainting mecha-
           nism didn't like.  The tainting mechanism is turned on
           when you're running setuid or setgid, or when you
           specify -T to turn it on explicitly.  The tainting
           mechanism labels all data that's derived directly or
           indirectly from the user, who is considered to be
           unworthy of your trust.  If any such data is used in a
           "dangerous" operation, you get this error.  See
           perlsec for more information.
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And looking at perlsec, we see all sorts of things that trigger such an error. In particular, you'll probably need to set $ENV{PATH} to an untainted value.