File::Spec can do the directory munging just as well and is a core module. Path::Class looks like a fine module, but adding the dependency isn't worth it for just one test case.
Patch pushed, please test and close
This bug is mentioned in: bug 5386: remove dep on Path::Class from t/00-load.t http://lists.koha-community.org/pipermail/koha-patches/2010-November/012902.html bug 5386: remove dep on Path::Class from t/00-load.t http://lists.koha-community.org/pipermail/koha-patches/2010-November/012912.html