Description of problem: I think the yum.conf manuel is incorrect. It states that the default for the « group_command » option is « compat ». But when testing, it seems that the default is in fact « object ».
Thanks for the report, will be fixed in the next f20 and rawhide release.
Confirming this is fixed in Fedora 20. yum-3.4.3-132.fc20.noarch
Closing this, since the bugfix is already in Fedora 20.