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.

here’s a quick and dirty way to teach ansi-color the aix color codes

(setq ansi-color-map
          [
           default bold
                           default italic underline bold bold-italic modeline
                           nil nil nil nil nil nil nil nil nil nil nil
                           nil nil nil nil nil nil nil nil nil nil nil
                           (foreground-color . "black")
                           (foreground-color . "dark red")
                           (foreground-color . "forest green")
                           (foreground-color . "dark orange")
                           (foreground-color . "dark blue")
                           (foreground-color . "dark magenta")
                           (foreground-color . "dark cyan")
                           (foreground-color . "light grey")
                           nil nil
                           (background-color . "black")
                           (background-color . "dark red")
                           (background-color . "forest green")
                           (background-color . "dark orange")
                           (background-color . "dark blue")
                           (background-color . "dark magenta")
                           (background-color . "dark cyan")
                           (background-color . "light grey")
                           nil nil nil nil nil nil nil nil nil nil nil
                           nil nil nil nil nil nil nil nil nil nil nil
                           nil nil nil nil nil nil nil nil nil nil nil
                           nil nil nil nil nil nil nil nil nil
                           (foreground-color . "dim grey")
                           (foreground-color . "red")
                           (foreground-color . "green")
                           (foreground-color . "gold")
                           (foreground-color . "slate blue")
                           (foreground-color . "magenta")
                           (foreground-color . "cyan")
                           (foreground-color . "white")
                           nil nil
                           (background-color . "dim grey")
                           (background-color . "red")
                           (background-color . "green")
                           (background-color . "gold")
                           (background-color . "slate blue")
                           (background-color . "magenta")
                           (background-color . "cyan")
                           (background-color . "white")
                           nil nil
                           ]
          )

If the mic doesn’t work in Skype, and your system does use PulseAudio (as most do these days) you might be missing alsa-plugins-pulse-32bit package on openSUSE / RPM or the lib32asound2-plugins on Debians

if you are experiencing mysterious crashes of various Gtk3 applications, giving BadWindow Error messages, often when using completion popups or dialogs, it might be because the Ubuntu version of gtk-vector-screenshot has unfixed bugs compared to the Debian one