bisect - Find the revision introducing a bug using a binary search

Version	(1, 1, 0, ‘pre’, 0)
Branch	lp:bzr-bisect
Home page	https://launchpad.net/bzr-bisect
GNU/Linux	Yes
Windows	Maybe (please test)
Mac OS X	Yes

Support for git-style bisection.

bisect

Purpose

Find an interesting commit using a binary search.

Usage

bzr bisect SUBCOMMAND [ARGS...]

Options

-v, --verbose	Display more information.
-h, --help	Show help message.
-q, --quiet	Only display errors and warnings.
--usage	Show usage message and options.
-o ARG, --output=ARG
	Write log to this file.
-r ARG, --revision=ARG
	See “help revisionspec” for details.

Description

Bisecting, in a nutshell, is a way to find the commit at which some testable change was made, such as the introduction of a bug or feature. By identifying a version which did not have the interesting change and a later version which did, a developer can test for the presence of the change at various points in the history, eventually ending up at the precise commit when the change was first introduced.

This command uses subcommands to implement the search, each of which changes the state of the bisection. The subcommands are:

bzr bisect start

Start a bisect, possibly clearing out a previous bisect.

bzr bisect yes [-r rev]

The specified revision (or the current revision, if not given) has the characteristic we’re looking for,

bzr bisect no [-r rev]

The specified revision (or the current revision, if not given) does not have the characteristic we’re looking for,

bzr bisect move -r rev

Switch to a different revision manually. Use if the bisect algorithm chooses a revision that is not suitable. Try to move as little as possible.

bzr bisect reset

Clear out a bisection in progress.

bzr bisect log [-o file]

Output a log of the current bisection to standard output, or to the specified file.

bzr bisect replay <logfile>

Replay a previously-saved bisect log, forgetting any bisection that might be in progress.

bzr bisect run <script>

Bisect automatically using <script> exit value to determine ‘yes’ or ‘no’.

Exit value	Meaning
0	Yes
125	Unknown (e.g. build failed so we could not test)
anything else	No