[phobos] bad git usage?

[Brad Roberts]

I don't know who's done what to piss off git, but 2 builds in the last 4 days have failed due to bad interactions with
github.  The auto-tester maintains a pristine tree that it just pulls into each cycle to get current code.  It _should_
be a simple fast-forward merge update every single time.  But twice it hasn't been:

Just now:

>From git://github.com/D-Programming-Language/phobos
 + d30bfde...c5cd017 HEAD       -> origin/HEAD  (forced update)
error: Ref refs/remotes/origin/master is at c5cd017921bb78644f8d130dc19c0df9e5b03bb5 but expected
d30bfdea40e768519aaa77170ee9e9697cbf685e
 ! d30bfde..fc5f620  master     -> origin/master  (unable to update local ref)

The last time:

>From git://github.com/D-Programming-Language/phobos
 + b64d9f2...c5cd017 HEAD       -> origin/HEAD  (forced update)
error: Ref refs/remotes/origin/master is at c5cd017921bb78644f8d130dc19c0df9e5b03bb5 but expected
b64d9f27c23dec08865d9eb624bf0d22b18e5637
 ! b64d9f2..d30bfde  master     -> origin/master  (unable to update local ref)

It looks like HEAD and master are out of sync, and from what I understand, that shouldn't happen.

The problematic commit:
   https://github.com/D-Programming-Language/phobos/commit/c5cd017921bb78644f8d130dc19c0df9e5b03bb5

But I'm not sure what's problematic about it.

Thoughts?

Thanks,
Brad