Re: bug#26608: channels.scm supporting substitutes

[Nome Grey <greynome72@gmail.com>]

Simon,

On Wed, Dec 4, 2019, 5:57 AM zimoun <zimon.toutoune@gmail.com> wrote:

> On Wed, 4 Dec 2019 at 13:40, Nome Grey <greynome72@gmail.com> wrote:
>
> >> Yes, as mentioned in my previous email I am working with the
> channels.scm file used by 'guix pull'.
> >>
> >> I installed a foreign distribution of guix 1.0.1 i686 using the binary
> installation steps from the manual.
> >>
>
> You do not have have to use all the code you found in the bug reports.
> It should work out-of-box with your current version of Guix.
>
> The channels are used with "guix pull -C /path/to/your/file.scm" and
> 'file.scm' respects the syntax presented here [1].
>
> [1] https://guix.gnu.org/manual/en/html_node/Channels.html#Channels


Thanks.  The problem is that old substitutes are not used on new guix
pulls, so upgrading takes unworkably long.  Pulling to the right commit, as
partly described in the bug reports, can make many more substitutes work,
and has helped me a lot.

>> I am currently running guix aca2bf5 but have a long-running process to
> downgrade to 1b6c5e8 in order to find a substitute for ungoogled-chromium 78
>
> To see if the substitute is available or not, the command "guix
> weather" fits your need [2].
>
> [2]
> https://guix.gnu.org/manual/en/html_node/Invoking-guix-weather.html#Invoking-guix-weather
>
>
> However, the package ungoogled-chromium 78 is not available for the
> system i686. You probably need to build it yourself (ressource
> consuming) with "guix build ungoogled-chromium".
>

I'm pretty sure I found just recently a successful build of
ungoogled-chromium-78 for i686-linux:
http://berlin.guixsd.org/build/1979882/details .  What do you think?

I misspoke with "downgrade": this build was for guix 1b6c5e8 which I am
trying to upgrade to in the hopes of using it.  I found it via the cuirass
api; it's evaluation 9047.

I am not sure that channel will help to fetch the result of any build.
> Channel helps to add more recipes about how to build packages. And I
> am not aware of other public substitutes server than
> https://ci.guix.gnu.org.
>

By only upgrading to releases with substitutes available, fewer builds are
required on the local system, which can still be occasionally brought up to
date.  The user channel filters the official channel, to hide releases
without substitutes built yet.

>