The security model for that might be, um, interesting.
You don't want to clone a particular revision ID, you want to clone a particular branch. If it "lives" in one known place, then its home can provide access control. But if it doesn't have a home like that, then everyone needs to have consensus on what's included and what's not. And you probably don't want to have to publicize a new repo/branch/whatever ID every time your committer list changes.
> You don't want to clone a particular revision ID, you want to clone a particular branch
Actually, that's exactly what I personally want for a bunch of things. I want to grab a very specific version of an item and know that I've got the one I expected.
You don't want to clone a particular revision ID, you want to clone a particular branch. If it "lives" in one known place, then its home can provide access control. But if it doesn't have a home like that, then everyone needs to have consensus on what's included and what's not. And you probably don't want to have to publicize a new repo/branch/whatever ID every time your committer list changes.