From abda001fcfc9ad99759ed3ebaeaa884c42f235cd Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 3 Jul 2014 09:16:14 +0530
Subject: [PATCH] Fix importing of C-extensions when people are running from
 source with a PYTHONPATH containing conflicting pre-imported modules

---
 src/calibre/constants.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 9e9e32f8a2..9356f5966f 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -160,6 +160,10 @@ class Plugins(collections.Mapping):
         if name in self._plugins:
             return
         sys.path.insert(0, sys.extensions_location)
+        try:
+            del sys.modules[name]
+        except KeyError:
+            pass
         try:
             p, err = importlib.import_module(name), ''
         except Exception as err: