--- pym/cache/cache_errors.py	(revision 9039)
+++ pym/cache/cache_errors.py	(working copy)
@@ -9,8 +9,11 @@ 
 	def __init__(self, class_name, error):
 		self.error, self.class_name = error, class_name
 	def __str__(self):
+		error_str = "'%s'" % str(self.error)
+		if hasattr(self.error, "errno"):
+			error_str += " errno=%d" % self.error.errno
 		return "Creation of instance %s failed due to %s" % \
-			(self.class_name, str(self.error))
+			(self.class_name, error_str)
 
 
 class CacheCorruption(CacheError):