Calling 'use' in global scope is forbidden and will be banned completely soon. Please fix the ebuilds to do all 'use' conditionals in phase functions.
Furthermore, DISTDIR is also forbidden in global scope.
Created attachment 433446 [details, diff] Proposed fix This attachment is a potential fix to the issues. I haven't tested it but after reading through kernel-2.eclass it looks like src_unpack() is the only place that the UNIPATCH stuff would be used from in this particular ebuild.
Ian, could you merge your patch, please? This will already cause fatal issues with git portage.
patch committed.