From e9fd7befb7817d3c9d580ee5a09292d4b3957716 Mon Sep 17 00:00:00 2001
From: Hugh Saunders <hugh@wherenow.org>
Date: Wed, 28 Jan 2015 12:48:46 +0000
Subject: [PATCH] Retry apt cache updates

---
 packaging/os/apt.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/packaging/os/apt.py b/packaging/os/apt.py
index b768c62c6de..d1a844ad738 100644
--- a/packaging/os/apt.py
+++ b/packaging/os/apt.py
@@ -706,7 +706,15 @@ def main():
                         updated_cache_time = int(time.mktime(mtimestamp.timetuple()))
 
             if cache_valid is not True:
-                cache.update()
+                for retry in xrange(3):
+                    try:
+                        cache.update()
+                        break
+                    except apt.cache.FetchFailedException:
+                        pass
+                else:
+                    #out of retries, pass on the exception
+                    raise
                 cache.open(progress=None)
                 updated_cache = True
                 updated_cache_time = int(time.mktime(now.timetuple()))