stderr_of_special_external_remotes_is_swallowed.mdwn

### Please describe the problem.

complicates troubleshooting of custom special remotes since annex seems to swallow all output, including stderr

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

5.20150302

> I have debugged external special remotes using stdderr, so I 
> know this is not the case. [[done]] --[[Joey]]