### Please describe the problem.

The command `git annex unused --from mys3remote` shows no unused data, when I'm expecting at least one old version of a file in the current directory.

### What steps will reproduce the problem?

- Create a file, `git annex add` the file, sync with remotes and copy to an amazon S3 special remote
- Run `git annex unlock` on the file, modify it, `git annex add` the file, sync and copy to S3
- Now if you run `git annex unused` you should see the old version of the file in the local repo
- But `git annex unused --from mys3remote` shows nothing
- And I know that the old version is on S3 (at least according to the logs) because `git annex whereis --unused` shows that the file is both [here] and [mys3remote]

I also noticed that the `git annex whereis --unused` command would show nothing if it was run directly after `git annex unused --from mys3remote`, but it would correctly show the locations when run directly after `git annex unused`.

### What version of git-annex are you using? On what operating system?

    git-annex version: 5.20141105-g8b19598
    build flags: Assistant Webapp Webapp-secure Pairing Testsuite S3 WebDAV Inotify DBus DesktopNotify XMPP DNS Feeds Quvi TDFA CryptoHash
    key/value backends: SHA256E SHA1E SHA512E SHA224E SHA384E SKEIN256E SKEIN512E SHA256 SHA1 SHA512 SHA224 SHA384 SKEIN256 SKEIN512 WORM URL
    remote types: git gcrypt S3 bup directory rsync web webdav tahoe glacier ddar hook external
    local repository version: 5
    supported repository version: 5
    upgrade supported from repository versions: 0 1 2 4

arch linux x86_64

### Please provide any additional information below.

The S3 remote is encrypted with the default "hybrid" method

[[!tag moreinfo]]
