+diff -u -r ../ghc-8.0.1/compiler/main/DriverPipeline.hs ./compiler/main/DriverPipeline.hs
+--- ../ghc-8.0.1/compiler/main/DriverPipeline.hs 2016-05-16 13:08:53.000000000 -0400
++++ ./compiler/main/DriverPipeline.hs 2016-09-07 03:37:48.321941122 -0400
+@@ -1831,10 +1831,7 @@
+ | WayThreaded `elem` ways dflags =
+ let os = platformOS (targetPlatform dflags)
+ in if os == OSOsf3 then ["-lpthread", "-lexc"]
+- else if os `elem` [OSMinGW32, OSFreeBSD, OSOpenBSD,
+- OSNetBSD, OSHaiku, OSQNXNTO, OSiOS, OSDarwin]
+- then []
+- else ["-lpthread"]
++ else []
+ | otherwise = []
+
+ rc_objs <- maybeCreateManifest dflags output_fn