It uses some code specific to Clang so I can't use gcc. I've got everything building but for some reason the 64bit builds fail for two binaries which rpmbuild can't link back to build-ids. 

As far as I can tell -g is being passed to clang for these binaries...

 

But the 32bit builds complete. I'm pretty much at a loss at this point and it's difficult to troubleshoot because I can't build locally. Mock even with --enablerepo=local is (was?) missing gcc-9.0.1. (no more mirrors to try). 

Thanks,

Richard