### Please describe the problem.
`git annex fsck --time-limit=` is broken. <br>
For one, there is a large delay between the specified time limit until something actually happens. With 20 seconds, `git annex fsck` always runs more than 5 minutes. And then something of the following happens: <br>
Sometimes it works as intended. <br>
Sometimes it prints "Time limit (20s) reached!" but hangs without exiting. <br>
Sometimes it prints "Time limit (20s) reached!" but continues fscking. <br>

### What steps will reproduce the problem?
In a sufficiently large repo run `git annex fsck --time-limit=20s`.

### What version of git-annex are you using? On what operating system?
8.20201127

> [[fixed|done]] --[[Joey]]
