bug#38528: Add test for `guix pull'

[zimoun]

Hi,

Thank Pierre to raise this issue.

On Sun, 8 Dec 2019 at 16:40, Pierre Neidhardt <address@hidden> wrote:

> The current way to do it is to run
>
>   guix pull --url=/path/to/checkout --profile=/tmp/guix.master

When I put that in a test -- say tests/guix-pull.sh -- troubles
arises... The main one appears because there is no user (chroot
environment I guess). Currently, Guix looks at $USER and $LOGNAME then
goes in "default" and applies "Migrating" profile code. Note that it
appears too with non login shell as reported here [1], perhaps not
related.

[1] https://lists.gnu.org/archive/html/guix-devel/2019-12/msg00021.html

What is the best:
    - set manually the variable USER to `whoami`?
or - change to scheme code to call `whoami`? Does Guile expose that?


All the best,
simon