Have you tested fLoadModules in isolation, by passing it a hardcoded string?

I think the original problem comes from this line, which assigns $modules the number of found modules:

my $modules    = fLoadModules $modules_path;
[download]

If you want to receive a list back instead of the number of modules, you need to have a list on the left hand side of the assignment:

my @modules    = fLoadModules $modules_path;
[download]