bug#22693: `guix refresh -u` updates other packages with same version

[Andreas Enge <andreas@enge.fr>]

On Tue, Feb 16, 2016 at 04:27:24AM -0500, Leo Famulari wrote:
> I've noticed that `guix refresh -u` will update extraneous packages if
> they happen to have the same version and be in the same module.
> 
> For example, from commit d694230ab, you can reproduce the bug:
> 
> $ ./pre-inst-env guix environment guix -- ./pre-inst-env guix refresh -u python-pytest
> $ git diff
> diff --git a/gnu/packages/python.scm b/gnu/packages/python.scm
> @@ -796,7 +796,7 @@ Python 3 support.")
>  (define-public python-pycrypto
>    (package
>      (name "python-pycrypto")
> -    (version "2.6.1")
> +    (version "2.8.7")
>  (define-public python-pytest
>    (package
>      (name "python-pytest")
> -    (version "2.6.1")
> +    (version "2.8.7")

I wondered about the "./pre-inst-env guix environment guix", but I tried it
without, and I confirm the problem.

Andreas