The incompatibility is more in the repo metadata than in yum -- yum 2.4.x (which is what's on the build hosts) doesn't understand the new comps format. And that's partly because the comps side of things has had a lot less thought and effort put into making sure that it covers the needs of the userbase. And I'm going to go out on a limb and say that I expect this _not_ to be the last time it changes... we're actually starting to use the information and so I'm all but certain that we'll find things that we hadn't considered.
While the new format is in certain ways better for the installer, you only need to change very few lines to make other apps use both the old format and the new format.
I think we should do more testing and put in more thoughts before pushing out changes for the comps.xml file. Especially if now further changes might get done over the next weeks. Shouldn't we then start a completely new file and only then add it to the other tools once its implementation is more complete?
I haven't chekd, but is the comps.xml file part of the repodata with defined content or is it just more "riding along" in the same directory?
Then mock has to grow how to parse a comps file. And which format should be preferred? If we were to go that route, we're better off just putting a list of packages in the mock config file, but that's just painful from a maintenance perspective, IMHO
Or just allow both ways. Doesn't make a too big difference until things get more standardized at some point.
regards,
Florian La Roche