From ce180227fa8a056a4128fd1e381c9ae5b83b1be7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Gra=C3=B1a?= <dangra@gmail.com>
Date: Wed, 10 Sep 2014 12:04:14 -0300
Subject: [PATCH] Twisted 11.1.0 (precise) can not deal with generators in
 DeferredList

Also create a list of the crawlers before iterating them because crawlers are removed from the set once stopped
---
 scrapy/crawler.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scrapy/crawler.py b/scrapy/crawler.py
index f18760390..ded09c1c7 100644
--- a/scrapy/crawler.py
+++ b/scrapy/crawler.py
@@ -107,7 +107,7 @@ class CrawlerRunner(object):
             crawler.signals.connect(log_observer.stop, signals.engine_stopped)
 
     def stop(self):
-        return defer.DeferredList(c.stop() for c in self.crawlers)
+        return defer.DeferredList([c.stop() for c in list(self.crawlers)])
 
     @defer.inlineCallbacks
     def join(self):