Wacom generic styli keep getting prepended to the key file
Plug in a Wacom Bamboo or a integrated Wacom panel (the ones in laptops, not the Cintiqs). All these have 'generic' styli without specific hardware IDs and/or serial numbers.
Open the wacom panel, bring the stylus into proximity. You'll get an entry like this as the stylus is mapped to the tablet for eternity:
$ cat $HOME/.cache/gnome-control-center/wacom/devices
[056a:00d1]
Styli=generic
That's intended and means next time we start the panel we already have the the mapping present for this tablet.
Quit, restart gnome-control-center and select the Wacom panel. Then bring the same stylus into proximity. Repeat a few times and you're left with:
$ cat $HOME/.cache/gnome-control-center/wacom/devices
[056a:00d1]
Styli=generic;generic;generic;
IOW the stylus is added each time it comes into proximity the first time after starting g-c-c.