From 8f631810870df78517ab2ba5279b3de229173a7c Mon Sep 17 00:00:00 2001
From: meh <meh@schizofreni.co>
Date: Fri, 18 Sep 2015 05:53:45 +0200
Subject: [PATCH] cargo: don't build when it's not set

---
 sys/Cargo.toml | 6 +++---
 sys/build.rs   | 4 ++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/sys/Cargo.toml b/sys/Cargo.toml
index 33ee268..601c0a3 100644
--- a/sys/Cargo.toml
+++ b/sys/Cargo.toml
@@ -19,9 +19,9 @@ default  = ["avcodec", "avdevice", "avfilter", "avformat", "avresample", "swresa
 static = []
 
 build          = ["static"]
-build-gpl      = []
-build-nonfree  = []
-build-version3 = []
+build-gpl      = ["build"]
+build-nonfree  = ["build"]
+build-version3 = ["build"]
 
 avcodec    = []
 avdevice   = ["avformat"]
diff --git a/sys/build.rs b/sys/build.rs
index ba2128e..413eac3 100644
--- a/sys/build.rs
+++ b/sys/build.rs
@@ -231,6 +231,10 @@ fn build() -> io::Result<()> {
 }
 
 fn main() {
+	if env::var("CARGO_FEATURE_BUILD").is_err() {
+		return;
+	}
+
 	println!("cargo:rustc-link-search=native={}", search().join("lib").to_string_lossy());
 
 	if fs::metadata(&search().join("lib").join("libavutil.a")).is_ok() {