Re: [Qemu-devel] PS/2 mouse support for FC4 guest broken in QEMU 0.9.1

[Johannes Schindelin]

Hi,

On Sun, 20 Jan 2008, Even Rouault wrote:

> After quite a lot of CVS bisection, [...]

Not wanting to advertise git, but to help other people needing to bisect 
efficiently: here is a recipe how to do this with git.

1. get git (obviously)

2. $ git clone git://repo.or.cz/qemu.git/
   (it is a git mirror of git://git.kernel.dk/data/git/qemu.git, so if you 
    do not want to be nice to Jens' server, you can go there directly)

3. Find out what was the last good revision.  If you have an approximate 
   date take the first "commit" of the output of

        $ cd qemu/
        $ git log --until="2007/09/07"

   (It would show a line beginning with "commit " and followed by a 
    40-character hex sequence; copy that sequence)

4. Start the bisection

        $ git bisect start
        $ git bisect bad HEAD
        $ git bisect good 85f8a4e8bae4df3983a5f1efd62b7942417bb89b

   Obviously, you have to use the sequence you copied in 3.

5. Compile, test, and call

        $ git bisect good

   or

        $ git bisect bad

   after the test, depending if the tested revision is good or -- you 
   guessed it -- bad.

6. Repeat 5. until git tells you which is probably the bad commit.  Then 
   scrap this clone, or go back to the CVS HEAD with

        $ git bisect reset

You are literally guaranteed to test the minimal amount of revisions with 
this procedure.

Hth,
Dscho