One simple possibility: split the ghc package up now. Initially create a "ghc-platform" subpackage in the same spec file, containing extralibs. Make the ghc package depend on ghc-platform, so it will be autoinstalled by a depsolver. When the real platform is released, split ghc into toplevel ghc and ghc-platform packages, chop out the ghc-platform subpackage from the ghc spec file, but don't rebuild the ghc package (since not necessary). A build of the new ghc-platform package should supersede the old subpackage (since rpm itself doesn't seem to know about subpackages at all).

I'd say, why not just keep ghc+extralibs together for now until platform is available? I don't really see any big win in doing it in two stages - just looks like extra effort to me. Then when platform is released we can drop extralibs from ghc if that makes sense, and push out ghc-platform in a timely manner. :)

Someone installing ghc after the splitup should get the old ghc and the new ghc-platform.

(We can't do that anyway, since that would leave the old subpackage still in the repo: so ghc needs to be updated anyway.)

I am happy to help review ghc-platform when it is ready. Will there be some pre-releases? :)

Jens