gb2048 reported @ https://moodle.org/plugins/view.php?plugin=local_codechecker that the latest version of the codechecker is displaying a lot or debug warnings about incorrect thirdpartylibs.xml paths.

Tracing down the problem, it seems that it's only under Windows where those problems are happening. For any other system (unix, mac) only 1 path should be reported (because it's incorrect 100%): lib/pear/Spreadsheet/Excel

So this is about to avoid the false positives under Windows.