SYNOPSIS
--------
-'git bisect' <subcommand> <options>
+'git bisect' <subcommand> <options>
DESCRIPTION
-----------
-The command takes various subcommands, and different options
-depending on the subcommand:
+The command takes various subcommands, and different options depending
+on the subcommand:
- git bisect start [<paths>...]
+ git bisect start [<bad> [<good>...]] [--] [<paths>...]
git bisect bad <rev>
git bisect good <rev>
git bisect reset [<branch>]
git bisect log
git bisect run <cmd>...
-This command uses 'git-rev-list --bisect' option to help drive
-the binary search process to find which change introduced a bug,
-given an old "good" commit object name and a later "bad" commit
-object name.
+This command uses 'git-rev-list --bisect' option to help drive the
+binary search process to find which change introduced a bug, given an
+old "good" commit object name and a later "bad" commit object name.
+
+Basic bisect commands: start, bad, good
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The way you use it is:
------------------------------------------------
$ git bisect start
-$ git bisect bad # Current version is bad
-$ git bisect good v2.6.13-rc2 # v2.6.13-rc2 was the last version
- # tested that was good
+$ git bisect bad # Current version is bad
+$ git bisect good v2.6.13-rc2 # v2.6.13-rc2 was the last version
+ # tested that was good
------------------------------------------------
-When you give at least one bad and one good versions, it will
-bisect the revision tree and say something like:
+When you give at least one bad and one good versions, it will bisect
+the revision tree and say something like:
------------------------------------------------
Bisecting: 675 revisions left to test after this
------------------------------------------------
-and check out the state in the middle. Now, compile that kernel, and boot
-it. Now, let's say that this booted kernel works fine, then just do
+and check out the state in the middle. Now, compile that kernel, and
+boot it. Now, let's say that this booted kernel works fine, then just
+do
------------------------------------------------
$ git bisect good # this one is good
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, you say "git bisect good" or "git bisect bad",
-and ask for the next bisection.
+and you continue along, compiling that one, testing it, and depending
+on whether it is good or bad, you say "git bisect good" or "git bisect
+bad", and ask for the next bisection.
+
+Until you have no more left, and you'll have been left with the first
+bad kernel rev in "refs/bisect/bad".
-Until you have no more left, and you'll have been left with the first bad
-kernel rev in "refs/bisect/bad".
+Bisect reset
+~~~~~~~~~~~~
Oh, and then after you want to reset to the original head, do a
$ git bisect reset
------------------------------------------------
-to get back to the master branch, instead of being in one of the bisection
-branches ("git bisect start" will do that for you too, actually: it will
-reset the bisection state, and before it does that it checks that you're
-not using some old bisection branch).
+to get back to the master branch, instead of being in one of the
+bisection branches ("git bisect start" will do that for you too,
+actually: it will reset the bisection state, and before it does that
+it checks that you're not using some old bisection branch).
+
+Bisect visualize
+~~~~~~~~~~~~~~~~
During the bisection process, you can say
to see the currently remaining suspects in `gitk`.
-The good/bad input is logged, and `git bisect
-log` shows what you have done so far. You can truncate its
-output somewhere and save it in a file, and run
+Bisect log and bisect replay
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The good/bad input is logged, and
+
+------------
+$ git bisect log
+------------
+
+shows what you have done so far. You can truncate its output somewhere
+and save it in a file, and run
------------
$ git bisect replay that-file
if you find later you made a mistake telling good/bad about a
revision.
-If in a middle of bisect session, you know what the bisect
-suggested to try next 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 want to find a near-by commit and try that
-instead. It goes something like this:
+Avoiding to test a commit
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If in a middle of bisect session, you know what the bisect suggested
+to try next 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
+want to find a near-by commit and try that instead.
+
+It goes something like this:
------------
$ git bisect good/bad # previous round was good/bad.
# was suggested
------------
-Then compile and test the one you chose to try. After that,
-tell bisect what the result was as usual.
+Then compile and test the one you chose to try. After that, tell
+bisect what the result was as usual.
+
+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 giving
+paths parameters when you say `bisect start`, like this:
+
+------------
+$ git bisect start -- arch/i386 include/asm-i386
+------------
-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 giving paths parameters when you say `bisect start`,
-like this:
+If you know beforehand more than one good commits, you can narrow the
+bisect space down without doing the whole tree checkout every time you
+give good commits. You give the bad revision immediately after `start`
+and then you give all the good revisions you have:
------------
-$ git bisect start arch/i386 include/asm-i386
+$ git bisect start v2.6.20-rc6 v2.6.20-rc4 v2.6.20-rc1 --
+ # v2.6.20-rc6 is bad
+ # v2.6.20-rc4 and v2.6.20-rc1 are good
------------
-If you have a script that can tell if the current
-source code is good or bad, you can automatically bisect using:
+Bisect run
+~~~~~~~~~~
+
+If you have a script that can tell if the current source code is good
+or bad, you can automatically bisect using:
------------
$ git bisect run my_script
------------
-Note that the "run" script (`my_script` in the above example)
-should exit with code 0 in
-case the current source code is good and with a code between 1 and 127
-(included) in case the current source code is bad.
+Note that the "run" script (`my_script` in the above example) should
+exit with code 0 in case the current source code is good and with a
+code between 1 and 127 (included) in case the current source code is
+bad.
-Any other exit code (a program that does "exit(-1)" leaves $? = 255,
-see exit(3) manual page, the value is chopped with "& 0377") will
-abort the automatic bisect process.
+Any other exit code will abort the automatic bisect process. (A
+program that does "exit(-1)" leaves $? = 255, see exit(3) manual page,
+the value is chopped with "& 0377".)
You may often find that during bisect you want to have near-constant
tweaks (e.g., s/#define DEBUG 0/#define DEBUG 1/ in a header file, or
GIT
---
Part of the gitlink:git[7] suite
-