Comment # 2 on bug 1175983 from Ulrich Windl

Created attachment 842059 [details]
Screenshot when trying to upgrade clang-devel from 7.01 to 9.01 in YaST

(In reply to Aaron Puchert from comment #1)
> If you need to keep one of those llvm7 subpackages, you can't have
> llvm-devel 9.

Two issues with that:
Aren't the package names "clang7" vs. "clang9" chosen to _allow_ co-existance
of both versions? And if not, wouldn't "Obsoletes:" package metadata help
zypper to resolve the conflict?