Re: Multi-OS Emacs buildbot?

[Pankaj Jangid]

Tim Landscheidt <tim@tim-landscheidt.de> writes:

> Git records the changes to the local repository in a refer-
> ence log.  One can access that with "git reflog" and/or "git
> rev-parse".  (For example:
>
> | [tim@passepartout ~/src/emacs]$ git rev-parse 'HEAD'
> | 2d790c6c57b244447390c023679752243e0049c9
> | [tim@passepartout ~/src/emacs]$ git rev-parse 'HEAD@{one.week.ago}'
> | 2d790c6c57b244447390c023679752243e0049c9
> | [tim@passepartout ~/src/emacs]$ git rev-parse 'HEAD@{two.week.ago}'
> | 67a8bdb90c9b5865b7f17290c7135b1a5458c36d
> | [tim@passepartout ~/src/emacs]$
>
> suggests that I last fetched the Emacs repository some time
> between one and two weeks ago.)
>
> So, untested, if you encounter a bug in HEAD, you could
> start the bisection, mark that commit as "bad", then iterate
> over HEAD@{1}, HEAD@{2}, etc. marking failures as "bad" com-
> mits as you go along, until you find a working commit, mark
> that as "good", and then start "git bisect run".

I didn’t know git has a builtin system like this. We were probably on
the same page. I was doing it outside git. Building previous commits in
reverse order and recording somewhere. Thanks for sharing this.

> (I hope it is clear that I'm not advocating against using CI
> systems; I just want to point out how one can narrow down a
> bug if either a repository does not have a CI system attach-
> ed or the CI system was not configured to track a particular
> bug.)

The two approaches have different context. CI is a centralized approach
where commits are comming and the system points out a faulty one and
informs the maintainers. The other approach is distributed. So many
people are already pulling code and building on their systems. Probably
a script can ask them, “*this* particular commit has issues, do you want
to report a bug?”. Of course, the later one covers only the platforms
which are most used and leave out the others. Lars has discovered that
so many *BSD builds are failing. Only a centralized system will be
effective in such a case.