From cf1ba31d7a454a129208cfde858e439bc02ea8da Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 22 Jan 2021 17:59:31 +0100
Subject: [PATCH] Hide rustc output by default.

But add an environment variable to allow showing it, if wanted.

Fixes #30
---
 src/lib.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index de50135..dae25d9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -249,6 +249,9 @@ impl AutoCfg {
         }
 
         command.arg("-").stdin(Stdio::piped());
+        if env::var_os("AUTOCFG_SHOW_RUSTC_OUTPUT").is_none() {
+            command.stderr(Stdio::null());
+        }
         let mut child = try!(command.spawn().map_err(error::from_io));
         let mut stdin = child.stdin.take().expect("rustc stdin");