From 0b85b87dc231ee3fb0533a54d6df351ed70c529b Mon Sep 17 00:00:00 2001
From: Chris Done <chrisdone@gmail.com>
Date: Tue, 17 Feb 2015 17:26:57 +0100
Subject: [PATCH] Use getNumCapabilities

---
 Stackage/ShakeBuild.hs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Stackage/ShakeBuild.hs b/Stackage/ShakeBuild.hs
index 5dc8fa65..156248c4 100644
--- a/Stackage/ShakeBuild.hs
+++ b/Stackage/ShakeBuild.hs
@@ -57,6 +57,7 @@ data Env = Env
 -- | Run the shake builder.
 performBuild :: PerformBuild -> IO ()
 performBuild pb' = do
+    num <- getNumCapabilities
     cur <- FP.getWorkingDirectory
     let shakeDir = cur <> "shake/"
     FP.createTree shakeDir
@@ -77,7 +78,7 @@ performBuild pb' = do
             }
     cleanOldPackages env
     printNewPackages env
-    startShake 2 shakeDir (shakePlan env)
+    startShake num shakeDir (shakePlan env)
 
 --------------------------------------------------------------------------------
 -- The whole Shake plan