Comment # 4 on bug 1227304 from huakim tylyktar

(In reply to huakim tylyktar from comment #3)
> (In reply to Adrian Schröter from comment #2)
> > yes, it is too late to do that at build time. The VM has no network and the
> > dependencies can not pre-calculated.
> > 
> > Either do that in default mode, so the change gets commited to the source.
> > 
> > Alternative is to use dynamic build dependency implementation where another
> > build job gets started in case dependencies are changing. That is a generic
> > rpm feature, supported by OBS by respawning a new job.
> > https://fedoraproject.org/wiki/Changes/DynamicBuildRequires
> > 
> > 
> > closing as works as designed.
> 
> But, maybe, we just need to add the feauture to order to respawn a new job
> before rpmbuild?

And, of course, with keeping generic rpm feauture.