Improve evaluator error message

Author: smowton

benchmarks/evaluator.py

@@ -101,7 +101,8 @@ def __compare_computed_and_expected_results(error_traces, record):
         return "The configuration JSON file does not containt \"data\" element under \"expected-results\"."
     expected_error_traces = record["expected-results"]["data"]
     if len(expected_error_traces) != len(error_traces):
-        return "Wrong number of sink locations for which error traces exist."
+        return "Wrong number of sink locations for which error traces exist (expected %d got %d)" % \
+          (len(expected_error_traces), len(error_traces))
     for expected_loc_idx in range(0, len(expected_error_traces)):
         expected_loc_traces = expected_error_traces[expected_loc_idx]
         loc_traces = None