Likely a reversion, but I have not checked.
joey@darkstar:~/bench>git clone 'annex::4cdb3781-ee3c-4830-b937-a2ec2015aebc?encryption=none&type=directory&directory=/home/joey/bench/d' xx
Cloning into 'xx'...
git-annex: /home/joey/tmp: createDirectoryFrom: not located in xx/.git: user error
Not limited to directory special remote, also happens with rclone. --Joey
Bisected the reversion to 835283b86240ef4b68c44f4332ac1b644e08e49f.
A createAnnexDirectory call gets added to fileRetriever in that commit, and that uses createDirectoryUnder. In the case of git-remote-annex, the destination file is not under the .git directory, and so it fails. Before this commit, it was retrieved to under the .git directory and then renamed into place, and that rename didn't care if the destination was not under .git.
Fixed by changing it to download to a path under .git
Also, this directory special remote case makes a good test case so I will add it to the test suite, which will be the first git-remote-annex in the test suite.