Re: How to avoid downloading qtbase:debug

[Maxim Cournoyer]

Hi,

Efraim Flashner <efraim@flashner.co.il> writes:

> On Sat, Oct 22, 2022 at 12:39:54PM +0200, Csepp wrote:
>> 
>> kiasoc5 <kiasoc5@disroot.org> writes:
>> 
>> > Dear Guix,
>> >
>> > =guix shell qtbase= downloads the entire debug output of qtbase even
>> > though I didn't write down qtbase:debug. That's hundreds of megabytes
>> > of bandwith I didn't want to use. How do I avoid downloading the debug
>> > output? Is this a bug?
>> 
>> I think it should be considered a bug.  guix shell always downloads
>> every output of all the packages.
>
> I assume it's related to grafts:
>
> (ins)efraim@3900XT ~$ guix shell qtbase@6
> 321.1 MB will be downloaded
>  qtbase-6.3.1-debug 287.7MiB 3.7MiB/s 00:01 [ ] 1.4%^C
> (ins)efraim@3900XT ~$ guix shell --no-grafts qtbase@6
> (ins)efraim@3900XT ~ [env]$
> exit
>
> Looks like it downloads all the outputs so it can perform grafts on all
> the outputs, and only then does it put just qtbase in the environment.

Yes, and this is because grafts have been marked as non-substitutable by
choice, for performance considerations.  Would revisiting this choice
helps here (making graft derivations substitutable?).

-- 
Thanks,
Maxim