From 9e9b8b17f829561c8fc4c34128e086536fd61277 Mon Sep 17 00:00:00 2001
From: Josh Stone <cuviper@gmail.com>
Date: Thu, 15 Feb 2018 00:00:31 -0800
Subject: [PATCH] Only build the threadpool if customized

---
 src/lib.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 8f2b6d2..49ea740 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -897,13 +897,13 @@ impl Build {
     fn compile_objects(&self, objs: &[Object]) -> Result<(), Error> {
         use self::rayon::prelude::*;
 
-        let mut builder = rayon::ThreadPoolBuilder::new();
         if let Ok(amt) = env::var("NUM_JOBS") {
             if let Ok(amt) = amt.parse() {
-                builder = builder.num_threads(amt);
+                let _ = rayon::ThreadPoolBuilder::new()
+                    .num_threads(amt)
+                    .build_global();
             }
         }
-        drop(builder.build_global());
 
         let results: Mutex<Vec<Result<(), Error>>> = Mutex::new(Vec::new());