QA/TDAI/RegressionRangeFinder

mozregression is a python command-line tool for finding a bug's regression range on Firefox nightly builds. Use the installation instructions for your platform.

As an example, if you know a bug wasn't present in the nightly for Feb 3 2009, but is present in today's nightly, you can run this command-line:

python regression.py -g 2009-02-03

This will download and run a series of nightly builds on a new, clean profile. When a new browser window pops up you can do whatever you need to do to verify the bugs presence in that build, then type 'good' or 'bad' into the prompt depending on whether the bug is present in that build:

After you've tried enough builds (about 7 for a 100-day initial regression range), you'll see something like this:

Last good nightly: 2009-12-22 First bad nightly: 2009-12-23

Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1f0e04dc2b21&tochange=f8b8f2f214d6

this is good information to paste into a Bugzilla comment. The pushlog url will show you all the code checkins that occurred during the regression range.

Other features

mozregression has a few command line options:

-b YYYY-MM-DD, --bad=YYYY-MM-DD	first known bad nightly build, default is today
-g YYYY-MM-DD, --good=YYYY-MM-DD	last known good nightly build *required
-e PATH1,PATH2, --extensions=PATH1,PATH2	list of extensions to install (path)
-p PATH, --profile=PATH	profile to use with nightlies (path)
-a ARG1,ARG2, --args=ARG1,ARG2	command-line arguments to pass to Firefox

Also, mozregression has a sister script, runnightly, that you can use to download and run a nightly from a particular date:

python runnightly.py -d 2010-02-15