If I add the corresponding line ("sys-cluster/openmpi -cuda") to package.use.mask I still get these errors from repoman:

 sys-cluster/openmpi/openmpi-1.7.3.ebuild: DEPEND: ~amd64-fbsd(default/bsd/fbsd/amd64/9.1) ['dev-util/nvidia-cuda-toolkit']
   sys-cluster/openmpi/openmpi-1.7.3.ebuild: RDEPEND: ~amd64-fbsd(default/bsd/fbsd/amd64/9.1) ['dev-util/nvidia-cuda-toolkit']

How do I get rid of those then?