* Prevent zombies. Previous the SIGCHLD handler only reaped one

zombie at a time, so if multiple children died before the handler
  got to run, some of them would not be cleaned up.

src/nix-worker/nix-worker.cc

@@ -534,7 +534,7 @@ static void processConnection()
 static void sigChldHandler(int sigNo)
 {
     /* Reap all dead children. */
-    while (waitpid(-1, 0, WNOHANG) == 0) ;
+    while (waitpid(-1, 0, WNOHANG) > 0) ;
 }