Re: Estimating build time

["Clément Lassieur" <clement@lassieur.org>]

Ludovic Courtès <ludo@gnu.org> writes:

> In a similar vein, the attached module provides code to estimate package
> build time based on locally-available build logs.  It can be used to
> show hints like this:

[...]

> The obvious downside is that it works by first retrieving the names of
> the files under /var/log/guix/drvs, and then opening, decompressing, and
> parsing the candidate log files.  That typically takes a few seconds on
> a recent SSD laptop, but clearly we don’t want to do that every time.
> We could maintain a cache, but even then, it might still be too
> expensive.
>
> Perhaps we should keep build times in the database somehow; the daemon
> can keep it up-to-date.
>
> Thoughts?
>
> There’s the obvious downside that both approaches rely on having
> previously built the package, but I think that’s a necessary limitation,
> unless we are to resort to external services (which could hardly provide
> estimates that make sense for the user’s machine anyway.)

I think it's an excellent idea!  I agree that the downside is necessary,
and yes, keeping the build times in the database sounds good!

Clément