here’s my personal summary

  • upgrade went very well. although not supported, a simple dist-upgrade worked like a charm

the only shock was after the first reboot. GRUB was broken. I didn’t even see the GRUB screen. The machine would be stuck in an endless reboot loop. BIOS screen → reboot → BIOS screen → reboot … Very puzzling issue that I haven’t been able to fix. I reinstalled the GRUB from Linux, and also from the grub prompt using (setup), to no avail.

In the end, I had to revert to my 11.2 GRUB version (funnily enough both are 0.97). I probably won’t have the energy to research this further.

What of course stopped working was my dirty multiseat hack. Instead of looping over the displays, I chose to loop over gnome sessions, because the new X is more securely set up so we need to steal the auth cookie to do what we want. setxkbmap also stopped accepting the “evdev” model, so I had to fix this by using -keycodes evdev -model pc104

As a bonus, I now know how to connect keyboards with different locales: use setxkbmap -device [`xinput list` ID here] -layout de (or -layout us)

Also, I opted to patch /usr/share/X11/xkb/symbols/sun_vndr/us again. Favorably, the BackSpace and AltGr key-bindings have been fixed, but the Alt and Meta keys have been broken.

Alt key got assigned Mod1 now, with Meta getting Mod4. No thanks, I don’t want to switch windows with Alt+Tab when my keyboard has Meta-keys in that place. So I had to switch the assignments for Mod1 and Mod4.