[[!comment format=mdwn
 username="joey"
 subject="""comment 5"""
 date="2017-07-10T18:15:02Z"
 content="""
Using trees like that would not work well in a distributed setting
where two repositories could be storing content on the same special remote.

The per-remote trees could be stored, by eg grafting them into the
git-annex branches's tree under the uuid of the special remote.

But, there could then be merge conflicts, when different trees have been
exported to the same special remote concurrently. And there's no way to
resolve such a merge: If repo A uploaded F containing K and B uploaded F
containing L, we don't know which file the special remote ended up with.
If that happened it would have to delete and re-export from scratch.

I think it's fine for exporting to only be able to be done from one
repository. But, if a user tries to do the above, it needs to fail in some
reasonable way, not leave a mess.
"""]]