"empty" driver disk with broken groups.xml causes silent error

[ydirson]

A Driver Disk generated with the DDK but with an error in groups.xml referencing a non-existent but mandatory package (<packagereq type="mandatory">update-</packagereq>) results in this during install:

     YUM: nothing to do
     YUM stderr: Warning: Group drivers does not have any packages to install.

... then the installer UI still reports the driver disk as "loaded", even though the package containing said driver has not been installed.

I realize this may originate in a problem with yum disregarding the "mandatory" type, but I'm stll quite new to package groups.