Comment # 13 on bug 1218184 from Dominique Leuenberger

(In reply to Jiri Srain from comment #12)
> Would there be an option to define (in ProjectConfig) new macros for this
> purpose and let the .spec-file handle the rest? This would allow to solve
> the issue with inheritance, one could override the inherited value of the
> macro in any project (and therefore solve the issue with inheriting prjconf
> from two repos)

That should be doable.. something like:

%repo_conf DEVEL
%if "%{_repository}" == "QA"
  %repo_conf QA
%endif

and then in the spec file:

%if "%{?repo_conf}" == "QA"
# for the regular spec files
ExclusiveArch: do-not-build
%endif
%if "%{?repo_conf}" == "DEVEL"
# for the QA flavors
ExclusiveArch: do-not-build
%endif

(needs some more conditions to trigger on the right flavors, but I think the
idea is clear)

ALP/Factory would not set repo_conf at all and thus get all flavors built (as
done in the past with the linked packages) - and the devel project has some
flexibility in overwriting the repo_conf marker (which is redefined multiple
times on inherited config, last one wins)