narrow the scope of the catch so that fewer errors are masked,

append the original error for user evaluation.

this still masks typos in the strfun code, because they're
indistinguishable from the strfun not allowed message,
and it's impossible to tell, client side, which is which.

Author: evanmcc

riak/mapreduce.py

@@ -277,10 +277,13 @@ def run(self, timeout=None):
         try:
             result = self._client.mapred(self._inputs, query, timeout)
         except RiakError as e:
-            for phase in self._phases:
-                if phase._language == 'erlang':
-                    if type(phase._function) is str:
-                        raise RiakError('may have tried erlang strfun when not allowed')
+            if 'worker_startup_failed' in e.value:
+                for phase in self._phases:
+                    if phase._language == 'erlang':
+                        if type(phase._function) is str:
+                            raise RiakError('May have tried erlang strfun '
+                                            'when not allowed\n'
+                                            'original error: ' + e.value)
             raise e
 
         # If the last phase is NOT a link phase, then return the result.

riak/tests/test_mapreduce.py

@@ -101,7 +101,8 @@ def test_erlang_source_map_reduce(self):
             [Value]
         end.""", {'language': 'erlang'}).run()
         except RiakError as e:
-            strfun_allowed = False
+            if e.value.startswith('May have tried'):
+                strfun_allowed = False
         if strfun_allowed:
             self.assertEqual(result, ['2', '3', '4'])