What is bibisect? And what is it doing in my office?

[Robinson Tryon]

On Tue, Jul 17, 2012 at 11:30 AM, Norbert Thiebaud <nthiebaud at gmail.com> wrote:
> On Sun, Jul 15, 2012 at 4:39 PM, Robinson Tryon
> <bishop.robinson at gmail.com> wrote:
>> Here's my first shot at bibisect integration into tinbuild2.
>
> Sorry, I've been afk for some time.. I'll be back soon.
> I took a quick glance, and up front:
>
> + I'd like not to create a new step for that but to fold it in the 'push' step

For clarity I'll keep the bulk of the code factored-out into a
separate function, but I'll have that function called from within
do_push(). If it's called deep inside do_push() (perhaps just before
prepare_upload_manifest), then we'll only get nightlies in the
bibisect repository, but we can always tweak it to use a strict
interval in the future.

> + I'd prefer if the global variable (and default) be step early
> (before sourcing the .tinbuild/config/<profile>.cfg so that they can
> easely be overridden there (notably the location of the 'artefact' git
> repo

I'll put all of the global variables right at the top of tinbuild2 --
the PUSH_TO_BIBISECT_REPO is already there. (I copied bjoern's naming
conventions for the variables -- I'm not sure why it's called ARTIFACT
DIR, but I'm sure there's a good reason!)

> + I suspect that a good part of the new bisect function should really
> be on the per-platform source, since it is likely that that will be
> quite different on Mac, Linux or Windows no ?

I think that all of the git and file operations should run on most
*nix systems, including OSX. There might be a couple of tweaks to make
sure that we use the right cross-platform switches for 'find', etc..
but nothing major.

Windows is a more...challenging creature. Whenever I've had to support
git on windows I've done it through cygwin. I believe that the cygwin
shell should have all of the command-line utils necessary for these
scripts to run, and I assume that windows buildbots have to run
tinbuild2 through cygwin (or something else that provides a bash
shell), so I hope (knock on wood) that these scripts will run cleanly
without any special porting code.

> I'll take a deeper look in few days, and probably take care of the
> first 2 items above, unless you beat me to it :-)

It is very beautiful outside today, but thankfully I can take my
laptop out under the tree and poke at the code from there, so I should
have some new diffs for you tonight :-)

--R