| diff --git a/rustc-1.29.0-src/src/vendor/libgit2-sys/build.rs b/rustc-1.29.0-src/src/vendor/libgit2-sys/build.rs | 
 | index 1e92dbc..883a0e4 100644 | 
 | --- a/rustc-1.29.0-src/src/vendor/libgit2-sys/build.rs | 
 | +++ b/rustc-1.29.0-src/src/vendor/libgit2-sys/build.rs | 
 | @@ -29,7 +29,9 @@ fn main() { | 
 |      if curl { | 
 |          register_dep("CURL"); | 
 |      } | 
 | -    let has_pkgconfig = Command::new("pkg-config").output().is_ok(); | 
 | +    let pkg_config = env::var_os("PKG_CONFIG") | 
 | +        .unwrap_or_else(|| "pkg-config".into()); | 
 | +    let has_pkgconfig = Command::new(pkg_config).output().is_ok(); | 
 |   | 
 |      if env::var("LIBGIT2_SYS_USE_PKG_CONFIG").is_ok() { | 
 |          if pkg_config::find_library("libgit2").is_ok() { |