[bug#28484] Some steps and questions for Cuirass

[Mathieu Othacehe <m.othacehe@gmail.com>]

Hi Jan,

> ...although that may be a feature?

I don't think so, patch 1 & 2 LGTM.

> Patch 3/3 is the one I'm least happy with.  When building many more packages
> than only `hello', Cuirass will not give any feedback until after everything
> is built.  The Emacs interface under M-x guix-hydra-latests-builds is very
> nice, but polling for that less so.
>
> As the comment in the file already says
>
>     ;; Register the results in the database.
>     ;; XXX: The 'build-derivations' call is blocking so we end updating the
>     ;; database potentially long after things have been built.
>
> we probably want feedback (or guix-hydra-latests-builds availability) per
> package...but any ideas how to do that?  We'd have to wrap/closure that into
> building the derivations?

Now that Cuirass supports M-x guix-hydra-latests-builds, the next step
is to detect build start/stop (maybe via guix build log parsing see:
https://lists.gnu.org/archive/html/guix-devel/2017-07/msg00221.html).

This way, for each new commit in guix, cuirass will only insert in
database the derivation that were built. Plus, it will be possible to
insert the build in db when it starts and update its status when it
stops/fails.

Until this is developed, patch 3 LGTM too !

Mathieu