The latest wxpython version 3.0.2.0-7 breaks the kicad UI since it's now compiled using GTK3 instead of GTK2.
I've added a package wxpython-gtk2 to the AUR which goes back to the previous behaviour. Maybe it's best to list it as dependency instead of wxpython?
The alternative is to disable wxpython scripting suppport for now, similar to how it's done in the stable kicad Arch package.
Pinned Comments