patch_do_patch() has the following assignment, with 'path' never being used after that. Seems to be a leftover. path = os.getenv('PATH')
Removed line, which indeed looks like it is unnecessary, and currently testing with a few builds.
The patch was sent to the mailing list on Apr 5th http://lists.openembedded.org/pipermail/openembedded-core/2016-April/119897.html