The only issue is the implicit function declaration in mocklibc, which has been meanwhile removed upstream (https://github.com/polkit-org/polkit/commit/8e17f09c770bc2efd5deb40ba2b6032d40603578). Because I do not exactly understand how the sub-project appears at the place where it does, I decided to resort to adding -Wno-error=implicit-function-declaration to %optflags. We should be able to remove the flag again after we pull from upstream again. I have created request https://build.opensuse.org/request/show/1187079