bug#23874: duplicates in manifests are “installed” more than once

[zimoun]

Dear,

Reminder: the manifest containing duplicates packages, such that:

--8<---------------cut here---------------start------------->8---
(use-package-modules admin)

;; so stressed!
(packages->manifest
 (list stress stress stress))
--8<---------------cut here---------------end--------------->8---

using “guix package -m manif.scm” leads to:

--8<---------------cut here---------------start------------->8---
The following packages will be installed:
   stress 1.0.4
   stress 1.0.4
   stress 1.0.4

[...]

building profile with 3 packages...
--8<---------------cut here---------------end--------------->8---

And, another UI issue:

--8<---------------cut here---------------start------------->8---
$ guix package -p /tmp/test -I
stress  1.0.4   out     /gnu/store/cm2fg1h2ad6v6zqwiiv1avg1mv2jzn66-stress-1.0.4
stress  1.0.4   out     /gnu/store/cm2fg1h2ad6v6zqwiiv1avg1mv2jzn66-stress-1.0.4
stress  1.0.4   out     /gnu/store/cm2fg1h2ad6v6zqwiiv1avg1mv2jzn66-stress-1.0.4
--8<---------------cut here---------------end--------------->8---


Note that the same kind of issue appears with:

--8<---------------cut here---------------start------------->8---
$ guix package -p /tmp/stress -i stress -i htop -i stress -i htop -i stress
The following packages will be installed:
   htop   3.0.1
   htop   3.0.1
   stress 1.0.4
   stress 1.0.4
   stress 1.0.4

[...]

building profile with 2 packages
--8<---------------cut here---------------end--------------->8---

but list the installed packages is correct:

--8<---------------cut here---------------start------------->8---
$ guix package -p /tmp/stress -I
htop    3.0.1   out     /gnu/store/pb0q52cfy7vld42xbnys26179wcm4k89-htop-3.0.1
stress  1.0.4   out     /gnu/store/cm2fg1h2ad6v6zqwiiv1avg1mv2jzn66-stress-1.0.4
--8<---------------cut here---------------end--------------->8---


On Thu, 30 Jun 2016 at 23:14, ludo@gnu.org (Ludovic Courtès) wrote:
> Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de> skribis:
>
>> No conflicts are reported, so no harm is done, but seemingly having the
>> very same package more than once in a profile might be confusing.
>>
>> Should Guix issue a warning when the same variable is referenced more
>> than once (I don’t like this because there really is no problem), or
>> should Guix delete duplicates from the list before creating a profile
>> generation?
>
> I think it should both delete duplicates, and then error out when two or
> more packages with the same name remain.  Further, this should take into
> account propagated inputs.

The duplicates in the list of ’packages->manifest’ could be deleted.  I
mean in guix/scripts/packages.scm:process-action tweak the
’concatenate-manifests’

--8<---------------cut here---------------start------------->8---
           (manifest (match files
                       (() (profile-manifest profile))
                       (_  (map-manifest-entries
                            manifest-entry-with-provenance
                            (concatenate-manifests
                             (map load-manifest files))))))
--8<---------------cut here---------------end--------------->8---

However, why should propagated inputs take into account?

> I think this is a pretty radical change, though, and I wonder about the
> amount of breakage it would create.  For instance, it means that one
> could create a profile containing both magit-referring-to-git-2.8 and
> git-2.9, or emms-referring-to-vorbis-tools-1.0 and vorbis-tools-2.0.
> Concretely, that means one will no longer be able to upgrade magit
> without also upgrading git, for instance (assuming they live in the same
> profile.)

Well, it seems going further that only detects the same package asked to
be installed several times with the same transaction.

All the best,
simon

For reference: <http://issues.guix.gnu.org/issue/23874>.