So, it appears my debacle has been observed before, all the way back in July 2014. Stephen Gallagher seems to have envisioned this situation as being as simple as removing one package and adding the other (or not having any of the fedora-release-* packages at all). However, after Mr. Gallagher himself pointed out a mechanical problem while testing such a switch, he seems to have hypothesized a special tool to allow users to switch between products. The conversation seems to end abruptly without a conclusion.
So, since I know not of the special tool’s existence, we might need some yum wizardry (or dnf) to fix me up here… Will think more and post later. Let me know if I’m missing an obvious solution or if you figure one out!
Some very useful information regarding this issue is found in bugzilla report 1160917. Some important pieces to this puzzle:
A good summary of the problem:
The Product-ization stuff has left us with a bit of a pickle regarding post-install addition of desktop groups – adding any other environment group to a Product install, or adding a Product environment group to any non-Product install.
If you install Fedora 21 and run ‘yum grouplist’, you will see the environment groups for all the various desktops we include – that is, you’ll see “Fedora Workstation” (which is actually the environment group ‘workstation-product-environment’), “KDE Plasma Workspaces” (which is actually the environment group ‘kde-desktop-environment’), “Xfce Desktop” (which is actually the environment group ‘xfce-desktop-environment’), and so on.
Unfortunately, you can’t actually install any of the other desktop environment groups if you installed Workstation. All the other desktop environment groups include the package group fedora-release-nonproduct , which simply pulls in the fedora-release-nonproduct package. So if you install Workstation then try ‘yum groupinstall KDE Plasma Workspaces’ or ‘yum install @^kde-desktop-environment’ (which do the same thing), it fails, because that wants to install fedora-release-nonproduct, which conflicts with fedora-release-workstation from your Workstation installation:
Error: fedora-release-workstation conflicts with fedora-release-nonproduct-21-0.16.noarch
Error: fedora-release-nonproduct conflicts with fedora-release-workstation-21-0.16.noarch
Similarly, if you install say the KDE live image, then try and install the “Fedora Workstation” group with yum, it’ll fail because it wants to install fedora-release-workstation, which conflicts with the installed fedora-release-nonproduct.
Regarding the inability to see the GNOME Desktop Environment package group:
You will *not* see the *package* groups for each desktop – ‘gnome-desktop’, ‘kde-desktop’, ‘xfce-desktop’ and so on. None of those is marked <uservisible>true</uservisible> in comps, so they do not appear in the list unless you pass an extra parameter.
The best work-around for running KDE on Fedora 21 Workstation which I have yet discovered is to install the KDE Plasma Workspaces group while excluding the fedora-release package:
yum groupinstall "KDE Plasma Workspaces" --exclude=fedora-release\*
However, I’m concerned about the dependency structure based around the fedora-release packages. More research is needed.