[bug#55220] [PATCH 0/4] Add --list-systems and --list-targets options.

["Ludovic Courtès" <ludo@gnu.org>]

Hello!

Mathieu Othacehe <othacehe@gnu.org> skribis:

> Most build commands support --system and --target options. Those options
> suffer from multiple issues: they are never listed and never checked.
>
> For --system, this is a real issue as aside from reading the (gnu packages
> bootstrap) module content the user cannot know what are the supported
> arguments. Providing a wrong system also fails badly:
>
> mathieu@meije ~$ guix build hello --system=arm-linux
> Backtrace:
> In guix/memoization.scm:
>     101:0 19 (_ #<hash-table 7f1d5d82a340 0/31> #<package tar@1.34 …> …)
>
> ...
> ice-9/boot-9.scm:1685:16: In procedure raise-exception:
> dynamic linker name not known for this system "arm-linux"
>
> For --target, any GNU supported triplet can possibly work but providing a
> wrong triplet will also fail badly:
>
> mathieu@meije ~$ guix build hello --target=arm-linux
> Backtrace:
> In guix/store.scm:
>    1385:9 19 (map/accumulate-builds #<store-connection 256.99 7f5bd…> …)
>  
>
> ...
> ice-9/boot-9.scm:1685:16: In procedure raise-exception:
> dynamic linker name not known for this system "arm-linux"
>
> This patchset adds two new options: --list-systems and --list-targets that
> list the supported systems and targets. The arguments passed to --system and
> --target options are also checked:
>
> mathieu@meije ~/guix [env]$ ./pre-inst-env guix build hello --system=arm-linux
> guix build: error: 'arm-linux' is not a supported system.

Nice.

> mathieu@meije ~/guix [env]$ ./pre-inst-env guix build hello --target=arm-linux
> guix build: error: 'arm-linux' is not a supported target.

Nice… but it’s a valid triplet (for freestanding binaries on 32-bit ARM,
I believe).

The ‘--target’ issue is tricky IMO because it’s mostly free-form.  In
(gnu packages …), there are calls like:

  (cross-gcc "avr" …)
  (cross-gcc "arm-none-eabi" …)
  (cross-gcc "propeller-elf" …)

These are unusual but valid triplets.

(I’m going to look more closely at the rest to get a more informed
opinion…)

Thanks for looking into this loooongstanding issue!

Ludo’.