### Please describe the problem.

There are multiple problems that have the same cause:

 * When using a shared repository (core.sharedrepository = group), the directories that contain the actual objects may be owned by different users. In this case adding or removing the sticky bit is prohibited by the operating system. Thus shared repositories can only be incrementally fscked if all objects are owned by the same user.

 * It is not currently possible to run incremental fscks on the local repository and on a special remote at the same time, because both of them use the same flag space, the sticky bit.

### What steps will reproduce the problem?

Create a shared repository (core.sharedrepository = group), let a different user add an object and then try to fsck it.

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

Debian's 4.20131106~bpo70+1

[[!tag confirmed]]
