From b453a8e616f489e077f8edcd95623b07484e7b8b Mon Sep 17 00:00:00 2001
From: Johannes Hofmann <johannes.hofmann@gmx.de>
Date: Fri, 2 Dec 2016 22:24:42 +0100
Subject: [PATCH] check waitpid() return value before setting exitStatus

This fixes a race with parallelBuild on DragonFly BSD.
---
 lib/pure/osproc.nim | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/pure/osproc.nim b/lib/pure/osproc.nim
index 76bd2dfe1d..f597bf7730 100644
--- a/lib/pure/osproc.nim
+++ b/lib/pure/osproc.nim
@@ -965,7 +965,7 @@ elif not defined(useNimRtl):
     var ret : int
     var status : cint = 1
     ret = waitpid(p.id, status, WNOHANG)
-    if WIFEXITED(status):
+    if ret == int(p.id) and WIFEXITED(status):
       p.exitStatus = status
     if ret == 0: return true # Can't establish status. Assume running.
     result = ret == int(p.id)