### Please describe the problem.


### What steps will reproduce the problem?

(1) Place a broken repo on a different mount point than the root partition.

(2) Run
    git annex repair.

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

 5.20131118-gc7e5cde on Ubuntu 12.04

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log

$ git annex repair --force

Running git fsck ...
git fsck found 74 broken objects.
Unpacking all pack files.
Unpacking objects: 100% (2307/2307), done.
Unpacking objects: 100% (241565/241565), done.
Re-running git fsck to see if it finds more problems.
Initialized empty Git repository in /tmp/tmprepo.0/.git/
Trying to recover missing objects from remote pi.fritz.box__var_lib_store_annex
Trying to recover missing objects from remote pi.fritz.box__var_lib_store_annex
74 missing objects could not be recovered!


Deleted remote branch pi.fritz.box__var_lib_store_annex/master (was dffa056).
error: Could not read 4e01bbdc7ce31247ad66ab13ca46925ac2c8db9a
fatal: Failed to traverse parents of commit 718525a48b4d6b3404eda5e189332d73c968a2be
Deleted remote branch pi.fritz.box__var_lib_store_annex/synced/git-annex (was 718525a).
Deleted remote branch pi.fritz.box__var_lib_store_annex/synced/master (was 9aedf69).
Deleted remote branch pi.fritz.box_annex/synced/master (was 92b1042).
Deleted remote branch store/master (was b059380).
removed 5 remote tracking branches that referred to missing objects
fatal: bad object refs/heads/git-annex
fatal: bad object refs/heads/git-annex
fatal: bad object refs/heads/git-annex
error: remote branch 'git-annex' not found.

git-annex: /tmp/packed-refs19813: rename: unsupported operation (Invalid cross-device link)
failed
git-annex: repair: 1 failed


# End of transcript or log.
"""]]

> Thanks for reporting. As far as I can see, this was fixed
> accidentially, when I rewrote the packed refs file handling code to not
> re-write the file. It had been using a temp file, and renaming it, thus
> the problem. I checked the repair code and can find no other probems
> of this sort currently in it. [[done]] --[[Joey]]
