In dev-util/catalyst-2.0_rc40 the fetchonly feature is broken in that it only performs fetching for the packages listed in the spec file. Once those items have been fetched it proceeds to run the chroot script for stage1 (I've only tested this using the stage1 spec files thus far) and that script builds packages. So essentially, I would expect fetchonly to mean that it only fetches the source.
Alright, I've fixed this for stages 1 through 3, livecd-stage1, and GRP. It will take a bit more for livecd-stage2, since it doesn't use run_emerge for its packages (except the kernel sources and genkernel).
Fixed in 2.0_rc42!
