"uild checkbox-gui only on supported architectures (i386, amd64, armhf).
The reason the others are unsupported is that the qt5declarative set of
packages depends on the v8 javascript engine which is unavailable for those
architectures. If/when this dependency becomes available we can either remove
these restrictions or leave the supported arch list "empty".
[r=sylvain-pineau][bug=][author=roadmr]"