Created attachment 319922 [details]
"-lm" is missing.
This was fixed in >=gnome-disk-utility-3.4.0
That one is not stable.
People disallowing underlinking and using stable arch are not able to compile gnome-disk-utility.
mh, weird. seems to be fixed in gnome-disk-utility-3.0.2-r201 probably because of the libgdu patch?
Anyway, since that is stable now too I'm fine.