kavya

perldiag says:

    '%s' trapped by operation mask
        (F) You tried to use an operator from a Safe compartment in which
        it's disallowed. See Safe.

Perl is a compiled/interpreted language (a.k.a P-coded, a.k.a. byte coded). That is, it compiles the code to low-level instructions which are then executed by the Perl run time.

The Safe module allows specific instructions to be disabled, and can be used when someone wants to run untrusted Perl.

It looks like your automated testing service has configured its testing system to disable flock. You will either need to work with them to get it enabled (if they are willing to do this) or find some way to do whatever it is you are doing without tickling this problem.

PS - You might get more traffic on a more Q&A-oriented forum like Perl Monks.