Hey Ludo,

On Mon, Feb 19, 2018 at 4:21 PM, Ludovic Courtès <ludo@gnu.org> wrote:
> Hi David!
>
> "Thompson, David" <dthompson2@worcester.edu> skribis:
>
>> In my lurkings I've seen people wondering why `guix environment`
>> doesn't work with manifests. The answer is simply: I never thought to
>> add it. This patch fixes that. The implementation is kind of
>> interesting and might seem a little silly to people that know how
>> manifests work.  In order to support manifests with minimal code and
>> make --manifest compose with other options I simply decompile the
>> manifest back into a list of package/output tuples.  That means in the
>> case of `guix environment --manifest=foo.scm` the manifest is created,
>> decompiled, and a new manifest created from that.  Seems redundant!
>> The advantage is that since --manifest composes with all the other
>> ways to specify packages we can do absolutely bonkers things like
>> `guix environment guile --ad-hoc ruby --manifest=foo.scm
>> --manifest=bar.scm --load=frob.scm --expression='(@ (gnu packages
>> python) python)'`.  More realistically you'd use it to throw in an
>> extra package or two with --ad-hoc.
>
> Indeed, that makes a lot of sense.  I wondered about doing that for
> ‘guix pack’ as well, it turns out to be more shenanigans than we’d like.
>
>> From 47e0cf3bef26791c72222175899790a46c49af45 Mon Sep 17 00:00:00 2001
>> From: David Thompson <dthompson2@worcester.edu>
>> Date: Thu, 15 Feb 2018 20:54:28 -0500
>> Subject: [PATCH] environment: Add --manifest option.
>>
>> * guix/scripts/environment.scm (show-help, %options): Add -m/--manifest.
>> (options/resolve-packages): Handle manifests.
>> * doc/guix.texi (Invoking guix environment): Document it.
>
> Could you add an example in tests/guix-environment.sh that uses a
> manifest with the “guile-bootstrap” package for instance?
>
> OK with this change!  :-)

Is this what you had in mind?

- Dave