rustpkg tests are broken on master

[Aatch]

The test in question is test_all and has been marked with #[ignore]. Seems to only happen on multi-host builds.

cc @catamorphism

[brson]

Example: http://buildbot.rust-lang.org/builders/snap3-mac/builds/320

[catamorphism]

Ok, I'll look at it.

[alexcrichton]

Probably the same bug as #7541

[catamorphism]

I think this should be fixed. Pushing to try.

[catamorphism]

Fixed by d9293d1