autobisectjs will help you to find out when a changeset introduced problems. It can also point at a changeset that may have exposed the issue.
It helps with work allocation:
- The engineer that most recently worked on the code is the one most likely to know how to fix the bug.
- If not, the engineer may be able to forward to someone more knowledgeable.
For SpiderMonkey, use the following while compiling locally:
<python executable> -m funfuzz.autobisectjs -p "--fuzzing-safe --no-threads --ion-eager testcase.js" -b "--enable-debug"
assuming the testcase requires "--fuzzing-safe --no-threads --ion-eager" as runtime flags.
This will take about:
- 45 - 60 minutes on a relatively recent powerful computer on Linux / Mac
- assuming each compilation takes about 3 minutes
- we should be able to find the problem within 16+ tests.
- 2 hours on Windows
- where each compilation is assumed to take 6 minutes.
If you have an internet connection, and the testcase causes problems with:
- a downloaded js shell
- these problems started happening within the last month
you can try bisecting using downloaded builds:
<python executable> -m funfuzz.autobisectjs -p "--fuzzing-safe --no-threads --ion-eager testcase.js" -b "--enable-debug" -T
This should take < 5 minutes total assuming a fast internet connection, since it does not need to compile shells.
Refer to compile_shell documentation for parameters to be passed into "-b".