bug#67290: (current-profile) only works when invoked as a process named "guix"

[Ian Eure]

Simon Tournier <zimon.toutoune@gmail.com> writes:

> Hi,
>
> On Sun, 19 Nov 2023 at 13:24, Ian Eure <ian@retrospec.tv> wrote:
>
> > The issue seems to be that current-profile checks the name of 
> > the
> > program which was invoked, and always returns #f unless the 
> > name ends
> > with "bin/guix".  Since "guile" doesn’t, they don’t work as 
> > expected.
> > See:
> > https://git.savannah.gnu.org/cgit/guix.git/tree/guix/describe.scm#n64
>
> About current-profile, maybe this patch:
>
> [2. p.patch --- text/x-diff; p.patch]
> diff --git a/guix/describe.scm b/guix/describe.scm
> index 65cd79094b..4147d5db1f 100644
> --- a/guix/describe.scm
> +++ b/guix/describe.scm
> @@ -61,14 +61,18 @@ (define current-profile
>  or #f if this is not applicable."
>      (match initial-program-arguments
>        ((program . _)
> -       (and (string-suffix? "/bin/guix" program)
> -            ;; Note: We want to do _lexical dot-dot 
> resolution_.  Using ".."
> -            ;; for real would instead take us into the 
> /gnu/store directory
> -            ;; that ~/.config/guix/current/bin points to, 
> whereas we want to
> -            ;; obtain ~/.config/guix/current.
> -            (let ((candidate (dirname (dirname program))))
> -              (and (file-exists? (string-append candidate 
> "/manifest"))
> -                   candidate)))))))
> +       (or (and (string-suffix? "/bin/guix" program)
> +                ;; Note: We want to do _lexical dot-dot 
> resolution_.  Using ".."
> +                ;; for real would instead take us into the 
> /gnu/store directory
> +                ;; that ~/.config/guix/current/bin points to, 
> whereas we want to
> +                ;; obtain ~/.config/guix/current.
> +                (let ((candidate (dirname (dirname program))))
> +                  (and (file-exists? (string-append candidate 
> "/manifest"))
> +                       candidate)))
> +           (let ((current (string-append
> +                           (config-directory #:ensure? #f) 
> "/current/manifest")))
> +             (and (file-exists? current)
> +                  current)))))))
>  
>  (define (current-profile-date)
>    "Return the creation date of the current profile (produced by 
>    'guix pull'),
>
>
> ?
>
> Well, I do not know exactly if fixing your issue does not 
> introduce
> regression.

The patch looks good to me, but this is all stuff I’m not very 
familiar with.


> About emacs-guix, instead of launching Guile, why not start 
> “guix
> repl” instead?  The command “guix repl” had been improved – and 
> maybe
> even introduced after the release of emacs-guix.  Somehow, I am 
> not very
> happy with the current integration between Geiser and Guix. :-)

I’m not sure why it works the way it does, or whether it could be 
changed to invoke `guix repl'.

I don’t think it’s expected for library code behavior to change 
depending on the runtime context, so I believe fixing Guix is the 
right solution.  Perhaps the concerns around resolving relative 
paths belongs somewhere more proximate to where that’s an issue? 
I definitely don’t understand everything happening in this code, 
but it strikes me as a concern relevant to some operations 
executed from the CLI.  If that’s the case, putting it in the CLI 
tooling where special handling is needed would make sense to me.

 — Ian