Re: Guix pull speed

[Josselin Poiret <dev@jpoiret.xyz>]

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Hi Simon,

Simon Tournier <zimon.toutoune@gmail.com> writes:

> Hi Josselin,
>
> On Tue, 29 Aug 2023 at 13:58, Josselin Poiret <dev@jpoiret.xyz> wrote:
>
>> After looking a bit more into guix pull speed, or to be more precise the
>> "Computing Guix derivation..." step, which is not substitutable.  I've
>> come to the conclusion that the thing that takes the majority of the
>> time is loading the files that define the packages that the new Guix
>> needs to build itself.
>
> Well, on my machine, the bigger bottleneck seems the procedure name
> ’proxy’ which copies stuff around, IIUC. See [1].

Proxy is on the helper script side, it's just waiting for the actual
build script to do its thing.

>>                         These files are not compiled yet, and worse,
>> loading just (gnu packages guile) ends up loading 361 other package
>> files.  You can generate a package graph in GraphML with `guix graph -t
>> module -b graphml guile`, and use e.g. networkx to analyze it.
>
> Hum, is this ’graphml’ something you have not submitted?  Or am I
> missing a point?  Last time I played with “guix graph”, I wrote a small
> script for bridging with networkx.  See [2].

I've committed it pretty recently, and should work OOTB now.

>> You can compare with a compiled check-out of guix by just running the
>> following in a `guix repl`:
>> --8<---------------cut here---------------start------------->8---
>> (use-modules (guix self) (guix monad-repl))
>> ,run-in-store (guix-derivation (getcwd) "0.0-git" #:pull-version 1)
>> --8<---------------cut here---------------end--------------->8---
>> which takes at most 5 seconds on my laptop.
>
> Yeah, that’s fast. :-)
>
> For comparing, what would be the corresponding derivations that “guix
> pull” is building?

It's building the same!  Just that building the derivation takes way
longer because it has first to load a bunch of uncompiled guile files.

Best,
-- 
Josselin Poiret

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