Re: Reproducible profiles

[ludo@gnu.org (Ludovic Courtès)]

David Thompson <dthompson2@worcester.edu> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:

[...]

>> What about instead requiring people to return a manifest:
>>
>>   (use-modules (guix profiles))
>>   (use-package-modules base emacs guile)
>>
>>   (manifest (cons (package->manifest-entry gcc-toolchain "debug")
>>                   (map package->entry
>>                        (list gcc-toolchain emacs guile-2.0))))
>>
>> That means we’ll have to document (guix profiles).
>>
>> It’s more verbose than what you suggest, though.  If you insist ;-), we
>> could allow a list of packages instead of a manifest, though I’d prefer
>> not to do that.
>
> Expecting a manifest always sounds good.  How about adding a convenience
> procedure for the (map package->entry ...) pattern since I think it will
> be the most common thing users will want to do?
>
>     (packages->manifest (list guile-2.0 guile-opengl guile-sdl))
>
> It could even support using other outputs like in that other example I
> gave:
>
>     (packages->manifest
>       (list guile-2.0
>             guile-opengl
>             guile-sdl
>             `(,gcc-toolchain "debug"))

Sounds good to me.

(FWIW I’m not fond of the `(,gcc-toolchain "debug") notation that we
also use in packages, but it has the advantage of being concise.)

>>> Below is a naive patch that does the job, but is unideal because it
>>> doesn't do some nice things like display the diff between generations
>>> before building.
>>
>> For that you would need a procedure to infer the manifest transaction:
>>
>>   (manifests->transaction m1 m2)
>>   ;; returns a <manifest-transaction>
>>
>> and then that could be passed to ‘show-manifest-transaction’.
>>
>> However, I’m not sure it’s very useful.  Perhaps it would be enough to
>> write “installing new manifest from foo.scm with 42 entries.”
>> WDYT?
>
> Okay, I'll do that instead.  I would be interested in seeing what has
> changed when I apply a new manifest, but it's probably not worth the
> effort right now.

Yeah.  And note that this can always be done from the wonderful guix.el
(info "(guix) Emacs List Buffer").

Thanks,
Ludo’.