From e529823635c8efee0d96a73fb90117ac81040710 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Wed, 10 Dec 2014 13:53:04 +0100
Subject: [PATCH] Don't wait for PID -1

The pid field can be -1 if forking the substituter process failed.
---
 src/libstore/local-store.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index fc48c0405..9bd03178e 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -358,7 +358,8 @@ LocalStore::~LocalStore()
             i->second.to.close();
             i->second.from.close();
             i->second.error.close();
-            i->second.pid.wait(true);
+            if (i->second.pid != -1)
+                i->second.pid.wait(true);
         }
     } catch (...) {
         ignoreException();