Just in case there is no gc module.

--HG--
branch : trunk
diff --git a/jinja2/testsuite/loader.py b/jinja2/testsuite/loader.py
index a46bda2..e6a552a 100644
--- a/jinja2/testsuite/loader.py
+++ b/jinja2/testsuite/loader.py
@@ -9,7 +9,6 @@
     :license: BSD, see LICENSE for more details.
 """
 import os
-import gc
 import sys
 import time
 import tempfile
@@ -134,7 +133,13 @@
 
         # unset all, ensure the module is gone from sys.modules
         self.mod_env = tmpl = None
-        gc.collect()
+
+        try:
+            import gc
+            gc.collect()
+        except:
+            pass
+
         assert name not in sys.modules