foreign-distro?

foreign-distro?

[jgart]

Does Guix have a declarative Guix API way of knowing if it is installing
a package into foreign distro versus Guix System?

I'm thinking of a function like `foreign-distro?`:

```
(define-public peek
  (package
   (name "peek")
   ...
(inputs 
  `(,@(if (foreign-distro?) `(("ffmpeg" ,ffmpeg)) '())))
```

The above includes ffmpeg in the inputs only if installing peek on a
foreign distro. It could additionally patch the ffmpeg executable in
a peek package phases if foreign-distro? returns #t.

WDYT

Re: foreign-distro?

[Julien Lepiller]

Le Sun, 20 Nov 2022 14:54:40 -0600,
jgart <jgart@dismail.de> a écrit :

> Does Guix have a declarative Guix API way of knowing if it is
> installing a package into foreign distro versus Guix System?
> 
> I'm thinking of a function like `foreign-distro?`:
> 
> ```
> (define-public peek
>   (package
>    (name "peek")
>    ...
> (inputs 
>   `(,@(if (foreign-distro?) `(("ffmpeg" ,ffmpeg)) '())))
> ```
> 
> The above includes ffmpeg in the inputs only if installing peek on a
> foreign distro. It could additionally patch the ffmpeg executable in
> a peek package phases if foreign-distro? returns #t.
> 
> WDYT
> 


Guix doesn't have a notion of foreign distro, it's all in your head,
and there's no difference between Guix System and other distros in the
Guix package manager's point of view :)

To be more specific, Guix only knows what you current system is (that's
captured by %current-system). It's probably x86_64-linux right know. As
you can see, there's no place in there to tell it whether you're on a
foreign distro or not.

Lastly, I don't think I would want to differentiate the two cases,
especially since it would mean that somehow Guix packages depend on
something external. There's this idea that Guix packages should somehow
be self-sufficient.

Re: foreign-distro?

[Jake Shilling]

[-- Attachment #1: Type: text/plain, Size: 2850 bytes --]


I've experimented with the distinction in my config, because I wanted to
be able to add home-services conditionally (e.g. I wanted my GuixSD to
install a destop envrionment, but my work laptop to only setup emacs and
its dependencies).

My approache was to just parse the `/etc/os-release` file if it exists:
```
(define (os-release)
  (guard (_
          (else #f))
    (call-with-input-file "/etc/os-release"
      (lambda (port)
        (let loop ((line (read-line port))
                   (result '()))
          (if (eof-object? line)
              (reverse result)
              (begin
                (let* ((split (string-split line #\=))
                       (key (string->symbol (car split)))
                       (val (if (string-match "\".*\"" (cadr split))
                                (substring (cadr split) 1 (- (string-length (cadr split)) 1))
                                (string->symbol (cadr split))))
                       (d (cons key val)))
                  (loop (read-line port)
                        (cons d result))))))))))
```

Then I define a couple wrappers:

```
(define (linux-distro-id)
  (if (linux?)
      (assq-ref (os-release) 'ID)
      #f))

(define (guix-system?)
  (eq? (linux-distro-id) 'guix))
```

The config was never really fleshed out because I ended up just using my
GuixSD computer for work instead.

On 2022-11-20 23:08, Julien Lepiller wrote:

> Le Sun, 20 Nov 2022 14:54:40 -0600,
> jgart <jgart@dismail.de> a écrit :
>
>> Does Guix have a declarative Guix API way of knowing if it is
>> installing a package into foreign distro versus Guix System?
>> 
>> I'm thinking of a function like `foreign-distro?`:
>> 
>> ```
>> (define-public peek
>>   (package
>>    (name "peek")
>>    ...
>> (inputs 
>>   `(,@(if (foreign-distro?) `(("ffmpeg" ,ffmpeg)) '())))
>> ```
>> 
>> The above includes ffmpeg in the inputs only if installing peek on a
>> foreign distro. It could additionally patch the ffmpeg executable in
>> a peek package phases if foreign-distro? returns #t.
>> 
>> WDYT
>> 
>
>
> Guix doesn't have a notion of foreign distro, it's all in your head,
> and there's no difference between Guix System and other distros in the
> Guix package manager's point of view :)
>
> To be more specific, Guix only knows what you current system is (that's
> captured by %current-system). It's probably x86_64-linux right know. As
> you can see, there's no place in there to tell it whether you're on a
> foreign distro or not.
>
> Lastly, I don't think I would want to differentiate the two cases,
> especially since it would mean that somehow Guix packages depend on
> something external. There's this idea that Guix packages should somehow
> be self-sufficient.
>

-- 
Best regards,
Jake Shilling

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: foreign-distro?

[Zhu Zihao]

[-- Attachment #1: Type: text/plain, Size: 881 bytes --]


If you want to left the choice to user. You can just don't patch it. Or
you can always patch it because user can still use package transformer
to specify a custom ffmpeg.


jgart <jgart@dismail.de> writes:

> Does Guix have a declarative Guix API way of knowing if it is installing
> a package into foreign distro versus Guix System?
>
> I'm thinking of a function like `foreign-distro?`:
>
> ```
> (define-public peek
>   (package
>    (name "peek")
>    ...
> (inputs 
>   `(,@(if (foreign-distro?) `(("ffmpeg" ,ffmpeg)) '())))
> ```
>
> The above includes ffmpeg in the inputs only if installing peek on a
> foreign distro. It could additionally patch the ffmpeg executable in
> a peek package phases if foreign-distro? returns #t.
>
> WDYT


-- 
Retrieve my PGP public key:

  gpg --recv-keys B3EBC086AB0EBC0F45E0B4D433DB374BCEE4D9DC

Zihao

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 255 bytes --]

Re: foreign-distro?

[Wojtek Kosior via Development of GNU Guix and the GNU System distribution.]

[-- Attachment #1: Type: text/plain, Size: 2139 bytes --]

Hi all,

Sorry to tell this - I don't think something like this would be even
possible to implement :/

AFAIK package definition fields like `(inputs)` don't just describe how
the package gets installed. They affect the actual build. So if we
really wanted this feature, we'd need to build 2 separate variants of a
package - one for Guix system and one for foreign distros.

In addition to looking like an overkill, such separate build variants
could also require changes to existing utilities like `guix copy`.

Besides all this, It it not that easy to determine whether Guix is
running under a foreign distro. One idea would be to check whether the
currently-running init system is Shepherd. But what if the user is
running Guix commands inside a Guix system chroot? The Shepherd process
is not going to be visible in such case

Wojtek

-- (sig_start)
website: https://koszko.org/koszko.html
PGP: https://koszko.org/key.gpg
fingerprint: E972 7060 E3C5 637C 8A4F  4B42 4BC5 221C 5A79 FD1A

Meet Kraków saints!           #18: blessed Józef Kowalski
Poznaj świętych krakowskich!  #18: błogosławiony Józef Kowalski
https://pl.wikipedia.org/wiki/Józef_Kowalski_(duchowny)
-- (sig_end)


On Wed, 23 Nov 2022 18:36:49 +0800
Zhu Zihao <all_but_last@163.com> wrote:

> If you want to left the choice to user. You can just don't patch it. Or
> you can always patch it because user can still use package transformer
> to specify a custom ffmpeg.
> 
> 
> jgart <jgart@dismail.de> writes:
> 
> > Does Guix have a declarative Guix API way of knowing if it is installing
> > a package into foreign distro versus Guix System?
> >
> > I'm thinking of a function like `foreign-distro?`:
> >
> > ```
> > (define-public peek
> >   (package
> >    (name "peek")
> >    ...
> > (inputs 
> >   `(,@(if (foreign-distro?) `(("ffmpeg" ,ffmpeg)) '())))
> > ```
> >
> > The above includes ffmpeg in the inputs only if installing peek on a
> > foreign distro. It could additionally patch the ffmpeg executable in
> > a peek package phases if foreign-distro? returns #t.
> >
> > WDYT  
> 
> 



[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 228 bytes --]