git bisect bad [<rev>]
git bisect good [<rev>...]
git bisect skip [(<rev>|<range>)...]
- git bisect reset [<branch>]
+ git bisect reset [<commit>]
git bisect visualize
git bisect replay <logfile>
git bisect log
------------------------------------------------
When you have specified at least one bad and one good version, the
-command bisects the revision tree and outputs something similar to:
+command bisects the revision tree and outputs something similar to
+the following:
------------------------------------------------
Bisecting: 675 revisions left to test after this
------------------------------------------------
-and then checks out the state in the middle. You would now compile
-that kernel and boot it. If the booted kernel works correctly, you
-would then issue the following command:
+The state in the middle of the set of revisions is then checked out.
+You would now compile that kernel and boot it. If the booted kernel
+works correctly, you would then issue the following command:
------------------------------------------------
$ git bisect good # this one is good
------------------------------------------------
-which would then output something similar to:
+The output of this command would be something similar to the following:
------------------------------------------------
Bisecting: 337 revisions left to test after this
------------------------------------------------
-and you continue along, compiling that one, testing it, and depending
-on whether it is good or bad issuing the command "git bisect good"
+You keep repeating this process, compiling the tree, testing it, and
+depending on whether it is good or bad issuing the command "git bisect good"
or "git bisect bad" to ask for the next bisection.
Eventually there will be no more revisions left to bisect, and you
Bisect reset
~~~~~~~~~~~~
-To return to the original head after a bisect session, you issue the
-command:
+After a bisect session, to clean up the bisection state and return to
+the original HEAD, issue the following command:
------------------------------------------------
$ git bisect reset
------------------------------------------------
-This resets the tree to the original branch instead of being on the
-bisection commit ("git bisect start" will also do that, as it resets
-the bisection state).
+By default, this will return your tree to the commit that was checked
+out before `git bisect start`. (A new `git bisect start` will also do
+that, as it cleans up the old bisection state.)
+
+With an optional argument, you can return to a different commit
+instead:
+
+------------------------------------------------
+$ git bisect reset <commit>
+------------------------------------------------
+
+For example, `git bisect reset HEAD` will leave you on the current
+bisection commit and avoid switching commits at all, while `git bisect
+reset bisect/bad` will check out the first bad revision.
Bisect visualize
~~~~~~~~~~~~~~~~
-During the bisection process, you issue the command:
+To see the currently remaining suspects in 'gitk', issue the following
+command during the bisection process:
------------
$ git bisect visualize
------------
-to see the currently remaining suspects in 'gitk'. `view` may also
-be used as a synonym for `visualize`.
+`view` may also be used as a synonym for `visualize`.
If the 'DISPLAY' environment variable is not set, 'git log' is used
instead. You can also give command line options such as `-p` and
Bisect log and bisect replay
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The good/bad input is logged, and:
+After having marked revisions as good or bad, issue the following
+command to show what has been done so far:
------------
$ git bisect log
------------
-shows what you have done so far. You can truncate its output somewhere
-and save it in a file, and run:
+If you discover that you made a mistake in specifying the status of a
+revision, you can save the output of this command to a file, edit it to
+remove the incorrect entries, and then issue the following commands to
+return to a corrected state:
------------
+$ git bisect reset
$ git bisect replay that-file
------------
-if you find later that you made a mistake specifying revisions as good/bad.
-
Avoiding testing a commit
~~~~~~~~~~~~~~~~~~~~~~~~~
-If in the middle of a bisect session, you know that the next suggested
+If, in the middle of a bisect session, you know that the next suggested
revision is not a good one to test (e.g. the change the commit
introduces is known not to work in your environment and you know it
does not have anything to do with the bug you are chasing), you may
For example:
------------
-$ git bisect good/bad # previous round was good/bad.
+$ git bisect good/bad # previous round was good or bad.
Bisecting: 337 revisions left to test after this
$ git bisect visualize # oops, that is uninteresting.
$ git reset --hard HEAD~3 # try 3 revisions before what
# was suggested
------------
-Then compile and test the chosen revision. Afterwards the revision
-is marked as good/bad in the usual manner.
+Then compile and test the chosen revision, and afterwards mark
+the revision as good or bad in the usual manner.
Bisect skip
~~~~~~~~~~~~
$ git bisect skip # Current version cannot be tested
------------
-But computing the commit to test may be slower afterwards and git may
-eventually not be able to tell the first bad commit among a bad commit
-and one or more skipped commits.
+But git may eventually be unable to tell the first bad commit among
+a bad commit and one or more skipped commits.
You can even skip a range of commits, instead of just one commit,
using the "'<commit1>'..'<commit2>'" notation. For example:
$ git bisect skip v2.5..v2.6
------------
-would mean that no commit between `v2.5` excluded and `v2.6` included
-can be tested.
+This tells the bisect process that no commit after `v2.5`, up to and
+including `v2.6`, should be tested.
Note that if you also want to skip the first commit of the range you
would issue the command:
$ git bisect skip v2.5 v2.5..v2.6
------------
-and the commit pointed to by `v2.5` would also be skipped.
+This tells the bisect process that the commits between `v2.5` included
+and `v2.6` included should be skipped.
+
Cutting down bisection by giving more parameters to bisect start
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You can further cut down the number of trials, if you know what part of
the tree is involved in the problem you are tracking down, by specifying
-path parameters when issuing the `bisect start` command, like this:
+path parameters when issuing the `bisect start` command:
------------
$ git bisect start -- arch/i386 include/asm-i386
or bad, you can bisect by issuing the command:
------------
-$ git bisect run my_script
+$ git bisect run my_script arguments
------------
Note that the script (`my_script` in the above example) should
revision (possibly with the needed patch) passed the test and then
rewind the tree to the pristine state. Finally the script should exit
with the status of the real test to let the "git bisect run" command loop
-to determine the eventual outcome of the bisect session.
+determine the eventual outcome of the bisect session.
EXAMPLES
--------
$ git bisect run make # "make" builds the app
------------
+* Automatically bisect a test failure between origin and HEAD:
++
+------------
+$ git bisect start HEAD origin -- # HEAD is bad, origin is good
+$ git bisect run make test # "make test" builds and tests
+------------
+
* Automatically bisect a broken test suite:
+
------------
outside the repository to prevent interactions between the bisect,
make and test processes and the scripts.
+* Automatically bisect a broken test suite:
++
+------------
+$ git bisect start HEAD HEAD~10 -- # culprit is among the last 10
+$ git bisect run sh -c "make || exit 125; ~/check_test_case.sh"
+------------
++
+Does the same as the previous example, but on a single line.
+
Author
------
Written by Linus Torvalds <torvalds@osdl.org>
-------------
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
+SEE ALSO
+--------
+link:git-bisect-lk2009.html[Fighting regressions with git bisect],
+linkgit:git-blame[1].
+
GIT
---
Part of the linkgit:git[1] suite