There's not a way I can see that we can implement what was discussed in #27112 without doing this; `depends_on :python` needs to indicate "bottle against a Homebrew Python and add that as a dependency when you're pouring a bottle". Additionally, we don't support pre-10.7 and I'm not sure what issues are going to be caused on those versions. I don't mind us fixing up that case but I don't think it should block this being included.