Comment # 17 on bug 1119186 from Aaron Puchert

(In reply to Luca Beltrame from comment #15)
> (In reply to Wolfgang Bauer from comment #14)
> 
> > That also means that we should probably better use "%requires_eq clang" to
> > force the "correct" version.
> 
> Agreed. This is probably the best way to go.

I think with https://phabricator.kde.org/D12331 and
https://phabricator.kde.org/D17858 in upstream this should no longer be
necessary. The last change will be contained in the next 5.3 update or 5.4.