$ cat ~/tmp/pm_11124087/lib/XYZ.pm
package XYZ;

1;

##</code><code>##

$ cat ~/tmp/pm_11124087/test_lib.pl
#!/usr/bin/env perl

use strict;
use warnings;

use lib 'lib';

use XYZ;

##</code><code>##

$ ./test_lib.pl
$ 

##</code><code>##

$ cd ..
$ pm_11124087/test_lib.pl
Can't locate XYZ.pm in @INC (you may need to install the XYZ module) (@INC contains: lib /home/ken/...

##</code><code>##

$ cat ~/tmp/pm_11124087/test_lib.pl
#!/usr/bin/env perl

use strict;
use warnings;

use FindBin;
use lib "$FindBin::Bin/lib";

use XYZ;

##</code><code>##

$ ./test_lib.pl
$ cd ..
$ pm_11124087/test_lib.pl
$