Auto merge of #4230 - Mark-Simulacrum:double-print, r=alexcrichton
authorbors <bors@rust-lang.org>
Tue, 27 Jun 2017 00:42:29 +0000 (00:42 +0000)
committerbors <bors@rust-lang.org>
Tue, 27 Jun 2017 00:42:29 +0000 (00:42 +0000)
commit854bc167bbf74053f821f65cb86d506033f3d3a7
tree37c197f8f64785bf2f92ff2d1af9c3ac87be110e
parenta3253d632f266f903f3bfaf3d925c3bd6bf7067f
parentf377ae2c93f7ccd7b749a43f9a2598e38e4ea05f
Auto merge of #4230 - Mark-Simulacrum:double-print, r=alexcrichton

Prevent rustc stderr/stdout from being duplicated.

Please review carefully. I've not submitted patches to Cargo before, I think, so this may be flawed in some way I haven't detected yet. Tests are green locally, though.

Fixes #4223