Handling test failures on re-test of good/bad revisions for confidence.

tools/auto_bisect/bisect_perf_regression.py

 #!/usr/bin/env python
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Chromium auto-bisect tool
 
 This script bisects a range of commits using binary search. It starts by getting
 reference values for the specified "good" and "bad" commits. Then, for revisions
 in between, it will get builds, run tests and classify intermediate revisions as
@@ skipping 2462 matching lines @@
        and good_state.passed not in ('Skipped', 'Build Failed')
        and bad_state.passed not in ('Skipped', 'Build Failed')):
       for state in (good_state, bad_state):
         run_results = self.RunTest(
             state.revision,
             state.depot,
             command_to_run,
             metric,
             test_run_multiplier=BORDER_REVISIONS_EXTRA_RUNS)
         # Is extend the right thing to do here?
-        state.value['values'].extend(run_results[0]['values'])
+        if run_results[1] != BUILD_RESULT_FAIL:
+          state.value['values'].extend(run_results[0]['values'])
+        else:
+          warning_text = 'Re-test of revision %s failed with error message: %s'
+          warning_text %= (state.revision, run_results[0])
+          if warning_text not in self.warnings:
+            self.warnings.append(warning_text)
 
 
 def _IsPlatformSupported():
   """Checks that this platform and build system are supported.
 
   Args:
     opts: The options parsed from the command line.
 
   Returns:
     True if the platform and build system are supported.
@@ skipping 356 matching lines @@
       # bugs. If you change this, please update the perf dashboard as well.
       bisect_utils.OutputAnnotationStepStart('Results')
     print 'Runtime Error: %s' % e
     if opts.output_buildbot_annotations:
       bisect_utils.OutputAnnotationStepClosed()
   return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())