adding a debug log to help figure out issues with filters.

ldapcherry/backend/backendLdap.py

@@ -261,6 +261,16 @@ class Backend(ldapcherry.backend.Backend):
         else:
             attrlist = None
 
+        self._logger(
+            severity=logging.DEBUG,
+            msg="%(backend)s: executing search "
+                "with filter '%(filter)s' in DN '%(dn)s'" % {
+                    'backend': self.backend_name,
+                    'dn': basedn,
+                    'filter': searchfilter
+                }
+        )
+
         # bind and search the ldap
         ldap_client = self._bind()
         try: