Comment # 6 on bug 1217257 from Christophe Marin

(In reply to Michal Suchanek from comment #5)
> I see, the build started failing when re2-11 was added to 15.6

if re2-10 is still available and updating Qt isn't an option, you can change
the BR to 'BuildRequires:  pkgconfig(re2) <= 10.0.0'