Didn't see anyone comment on this, but: use lib '.'; is basically a no-op (unless you're root, where that's removed).

Actually, I had a use for this today. I have PERL5LIB set to some custom locations, but had a test version of a library in the current directory. I needed 'use lib qw(.)' in my test program in order to override what PERL5LIB had in it. Or I could've put "." at the front of PERL5LIB...yeah, it's a different intent than what you (probably correctly) assumed from the OP, but it's not completely a "no-op" :-)