### Please describe the problem.
After a clean install of the latest git-annex for Windows (https://downloads.kitenet.net/git-annex/windows/current/), most git-annex commands fail with the following error message:
    
    git-annex: System.PosixCompat.User.getEffectiveUserID: not supported: illegal operation

### What steps will reproduce the problem?

    git init
    git annex init

Running for example `git annex version` or `git annex info` gives the same error message.


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

git-annex version should be 5.20141024, but the installer does not specify version and `git annex info` does not work, so it is hard to tell for sure.
Running Windows 7, x64. Also tried running as administrator and in a cmd.exe shell as well as Powershell.


### Please provide any additional information below.

The `git annex test` command does work, and all 84 tests passes.

> [[fixed|done]]; I was able to reproduce this bug, and it was crashing
> trying to look up the geckos username. I don't understand why this worked
> before; some change exposed this code path on Windows. In any case, I've
> fixed the crash, and I will be updating the windows builds with this bug
> fix. --[[Joey]]
