Re: Branch with only available substitutes ?

[zimoun <zimon.toutoune@gmail.com>]

Hi,

In case you missed it:

<https://guix.gnu.org/en/manual/devel/en/guix.html#Channels-with-Substitutes>

which does not solve the issue but helps. :-)


On Sun, 9 Jan 2022 at 22:10, Nicolas Graves via Development of GNU
Guix and the GNU System distribution. <guix-devel@gnu.org> wrote:

> I find myself often waiting for heavy packages (ungoogled-chromium,
> cargo...) to be built as substitutes before updating my system and I
> find it a bit long to my personal taste.
>
> Would it be possible to add a branch in guix sources following only
> available substitutes, so that each time I pull, I can immediatly
> and quickly update. Or would that need to stay as someone's personal
> project ?

Adding what you are proposing would not change your "complaint". ;-)
Each time you would pull, you would stay on the same revision because
the substitutes would not be ready yet and so no quick update.  You
would have to wait and run again "guix pull" later, probably staying
on the same revision because the substitutes would not be ready.  In
the meantime, you would miss new features or new security fixes for
others of some packages you are using.

However, I agree that's annoying.  Some time ago (before the link
above), I used a script along these lines:

--8<---------------cut here---------------start------------->8---
#!/bin/bash

# url-cache-directory from guix/git.scm
# pjmkgl... = hash("https://git.savannah.gnu.org/git/guix.git")
CACHE=~/.cache/guix/checkouts
CHECKOUT=${CACHE}/pjmkglp4t7znuugeurpurzikxq3tnlaywmisyr27shj7apsnalwq

printf "Updating local checkout:\n'$CHECKOUT'..."
git -C $CHECKOUT fetch -q
echo " done."

guix pull --commit=$(git -C $CHECKOUT                                    \
                         log                                             \
                         --before=$(date --date='2 weeks ago' +%Y-%m-%d) \
                         --format="%h" | head -n1)                       \
     $@

echo "done."
exit 0
--8<---------------cut here---------------end--------------->8---

to lag by 2 week behind origin/master and so be almost sure to have
the substitutes -- if their build success-ed. ;-)

Well, yeah it's annoying to run "guix pull", check with "guix
weather", and depending on the result upgrade or not -- note that the
exit status cannot be used [1].  When all that could be automatized.
#47929, as Mathieu said, is grouping "guix pull" and "guix weather".
Maybe we could imagine an option to "guix upgrade" coupling "guix
weather"; somehow the converse of 'no-substitutes' or the converse of
'fallback', i.e., do not try to locally build if the substitutes is
not available.  I do not know.

1: <https://yhetil.org/guix/YOdhd7FfMOvKjTQe@jasmine.lan/>

Cheers,
simon