Description of problem:

To quote myself from the recent ml discussion: 

Well you assume that buildep is only used to build packages. But if
you want to build the upstream source of a package for any reason
having a command that installs required packages is handy.

For instance if I want to build "foo" to write / test a patch I do
"yum-builddep foo" "jhbuild buildone foo" ... I have the code, can
hack on it, can build it without messing with deps and do not have to
build a package (development does not always mean "packing").


i.e it should work like yum where having a srpm / spec file is not required.