The new Fedora upgrade process by and large worked very well for me. The one exception was logins to Gnome. Read on.
I have done the Fedora 19 to 20 upgrade on a number of disparate systems now. In the main these upgrades were not a painful experience and could be classified a success.
Except for the Gnome login.
For some reason every one of my upgraded systems has an issue with the login, or rather, lock screen, process.
The symptoms are the same in every case: User logs out (or machine reboots) and the new Gnome “screen shield” (which I’ve sometimes called the “screen shade”, because that’s what it looks like) pops up. When you swipe it up or hit ESC to reveal the username field that field is grayed out. To log in you have to put the focus in the field (usually by clicking into it with the mouse) and then hit enter before you can enter your username. If you enter your username before hitting enter the username field will clear and present a blank copy of itself again.
This was pretty annoying, but got serious when I wasn’t able to log into one machine at all, it simply wouldn’t take my well-known password. Breaking out required a reboot, something you just shouldn’t ever need to do on a Linux machines (I probably should have just tried a “systemctl gdm restart”, but I was pissed by that point).
I tried a bunch of different things to fix it, up to and including recreating the user’s home directory and only restoring the non-desktop environment files (including dotfiles) from backup. Nothing worked. Except turning off “Blank screen” in the Gnome Control Center for the gdm user.
xhost +SI:localuser:gdm sudu -u gdm gnome-control-center
Then go to Power… Blank screen and set to “None”.
(I did try “Privacy… Screen Lock… Off”, but it didn’t have any effect)
To make the change effective I did a reboot, because by now the whole gnome login system is such a morass and I don’t have the patience for it anymore.
I put up a question on ask.fedoraproject.org a few days ago without getting any responses (Why does “ask” insist on your using a social media login for authentication, anyway? Do the developers own stock in Google, Twitter, Facebook, et. al., or are they just getting paid by them?).
Hopefully whatever the problem is will get fixed before Fedora 21, although given the track record of issues with the Gnome login (why exactly did we need a mobile phone-type screen shade on a desktop system?), I’m not going to hold my breath.