rust-lang/rust — pull request #18985 by alexcrichton (2014-11-15 19:24:39+00:00)
Title: std: Fix a flaky test on OSX 10.10

This test was somewhat sketchy already with a `loop` around `write`, so this
just adds some explicit synchronization to only call `write` once and guarantee
that the error happens.

Closes #18900