A very uninformative exception is raised sometimes when compare_samples try to read a file via xhr synchronously, see
https://build.chromium.org/p/tryserver.chromium.perf/builders/staging_win_perf_bisect/builds/20/steps/Re-testing%20reference%20range.Compare%20samples/logs/stdio
This seems to happen in Windows, but without a more explicit exception we cannot be sure as to the cause.
In case the log is purged the traceback for the exception in question is:
Traceback (most recent call last):
File "C:\b\c\b\staging_win_perf_bisect\catapult\tracing\bin\compare_samples", line 54, in <module>
sys.exit(Main(sys.argv))
File "C:\b\c\b\staging_win_perf_bisect\catapult\tracing\bin\compare_samples", line 48, in Main
args.format
File "C:\b\c\b\staging_win_perf_bisect\catapult\tracing\tracing\metrics\compare_samples.py", line 54, in CompareSamples
metric
File "C:\b\c\b\staging_win_perf_bisect\catapult\third_party\vinn\vinn\_vinn.py", line 186, in RunFile
return _RunFileWithD8(temp_boostrap_file, js_args, v8_args, stdout, stdin)
File "C:\b\c\b\staging_win_perf_bisect\catapult\third_party\vinn\vinn\_vinn.py", line 265, in _RunFileWithD8
'Exception raised when executing %s:\n%s' % (js_file_path, out))
RuntimeError: Exception raised when executing c:\users\chrome~1\appdata\local\temp\tmptm7exf\_tmp_boostrap.js:
/tracing/base/xhr.html:123: Error loading file
return read(filename);
Comment 1 by sullivan@chromium.org
, Oct 27 2016