If USE="acl" is enabled, vim (and gvim and kvim) DEPEND upon sys-apps/acl . Unfortunately, acl isn't stable on sparc (or several other archs for that matter). Not sure what the best way to handle this is. I can't even get acl to compile on sparc, so keywording stable doesn't seem to be an option. Suggestions?
Fixed Basically, this as well as attr was setting PKG_PLATFORM to sparc-unknown-linux-gnu or sparc64-unknown-linux-gnu in include/builddefs. When comparing it to an x86 host, they had it set to linux, so I touched up all the ebuilds with a little sed-fu to fix this and they build happily. How well they work is an entirely different question :-P