--- a/rtags.py	Tue Sep 15 18:43:19 2015 +0200
+++ b/rtags.py	Mon Oct 05 17:10:36 2015 +0200
@@ -97,7 +97,7 @@
     def init(self, schema, check=True):
         # XXX check existing keys against schema
         if check:
-            for (stype, rtype, otype, tagged), value in self._tagdefs.items():
+            for (stype, rtype, otype, tagged), value in list(self._tagdefs.items()):
                 for ertype in (stype, rtype, otype):
                     if ertype != '*' and not ertype in schema:
                         self.warning('removing rtag %s: %s, %s undefined in schema',