Whoa, hang on there.

system is a perl built-in function, so you do not need any modules installed to have it available.

lockfile is part of your operating system software (well, that's not technically completely accurate, but close enough), so it has nothing to do with Perl in itself.

Back out of that alley you've gone down and look for the solution in another direction :). Your problem is most probably situated in different behaviour of lockfile between your original and current systems.