$ mkdir foo

$ cat > foo/Module.pm
package Module;

use Cwd         qw( realpath );
use Path::Class qw( file );

print( "absolute: ", file(__FILE__)->absolute->dir, "\n");
print( "realpath: ", file(realpath(__FILE__))->dir, "\n");

1;

$ perl -Mlib=foo -e'use Module'
absolute: /tmp/ikegami/foo
realpath: /tmp/ikegami/foo

$ ln -s foo bar

$ perl -Mlib=bar -e'use Module'
absolute: /tmp/ikegami/bar
realpath: /tmp/ikegami/foo

$ mkdir baz

$ ln -s ../foo/Module.pm baz/Module.pm

$ perl -Mlib=baz -e'use Module'
absolute: /tmp/ikegami/baz
realpath: /tmp/ikegami/foo