But your code also in turn pulls in those libs! Let's experiment:

$ cat <<END >in-yours
use File::Spec;
use File::Basename;
use lib &dirname(File::Spec->rel2abs($0));

print "$_\n" for sort keys %INC;
END
$ perl in-yours >out-yours
$ cat <<END >in-mine
use FindBin qw($Bin);
use lib $Bin;

print "$_\n" for sort keys %INC;
END
$ perl in-mine >out-mine
$ comm out-yours out-mine
        Carp.pm
        Config.pm
        Cwd.pm
        Exporter.pm
    Exporter/Heavy.pm
        File/Basename.pm
        File/Spec.pm
        File/Spec/Unix.pm
    FindBin.pm
        XSLoader.pm
        attributes.pm
        base.pm
        lib.pm
        re.pm
        strict.pm
        vars.pm
        warnings.pm
        warnings/register.pm
$
[download]

So, the only differences are FindBin itself and Exporter::Heavy. Your attempt to avoid Cwd, Carp, and Config are not avoided in the slightest.

So please, don't try to reinvent the wheel until you know what that wheel is doing.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.