Hi Guix!

There seems to be a bug with the --network flag to `guix system
container', if we try to use docker-image.tmpl as an example we get the
following failure:

--8<---------------cut here---------------start------------->8---
$ sudo `guix system container -v3 --network gnu/system/examples/docker-image.tmpl`
Password:
system container is running as PID 17630
WARNING: (guile-user): imported module (guix build utils) overrides core binding `delete'
Run 'sudo guix container exec 17630 /run/current-system/profile/bin/bash --login'
or run 'sudo nsenter -a -t 17630' to get a shell into it.

WARNING: (guile-user): imported module (guix build utils) overrides core binding `delete'
making '/gnu/store/2w0c609is7iilv6r2l1vrchb9qsbfgkp-system' the current system...
WARNING: (guile-user): imported module (guix build utils) overrides core binding `delete'
setting up setuid programs in '/run/setuid-programs'...
populating /etc from /gnu/store/ywsdjyq161a2clhvz6kx5m4ppz5ziqp1-etc...
Backtrace:
          11 (primitive-load "/gnu/store/5wdqg0jpiw1zd9pn13wmzy3f85g…")
In gnu/build/linux-container.scm:
    300:8 10 (call-with-temporary-directory #<procedure 7fa5741fdd70…>)
   397:16  9 (_ "/tmp/guix-directory.KgjoQ6")
     62:6  8 (call-with-clean-exit #<procedure 7fa57420fd40 at gnu/b…>)
In unknown file:
           7 (primitive-load "/gnu/store/2w0c609is7iilv6r2l1vrchb9qs…")
In ice-9/eval.scm:
    619:8  6 (_ #f)
In unknown file:
           5 (primitive-load "/gnu/store/xfd58fw9x65n7wr5kw2gnciszkl…")
In srfi/srfi-1.scm:
    634:9  4 (for-each #<procedure primitive-load (_)> _)
In unknown file:
           3 (primitive-load "/gnu/store/3gwb0jydx90f61a6kizawsjdi6h…")
In srfi/srfi-1.scm:
    634:9  2 (for-each #<procedure 7fa57410e0e0 at gnu/build/activa…> …)
In gnu/build/activation.scm:
   268:20  1 (_ "hosts")
In unknown file:
           0 (copy-file "/etc/static/hosts" "/etc/hosts")

ERROR: In procedure copy-file:
In procedure copy-file: Read-only file system
--8<---------------cut here---------------end--------------->8---

Doing a git bisect, the problem started with this commit it seems:
802ea1f3a43e5fb8d0b8bd2882954d8a6e49cde6

--8<---------------cut here---------------start------------->8---
system: Deprecate hosts-file.

* gnu/system.scm (operating-system-hosts-file): Deprecate procedure.
(warn-hosts-file-field-deprecation): New procedure, helper for
deprecated variable.
(operating-system)[hosts-file]: Use helper to warn deprecated field.
(local-host-aliases): Mark as deprecated.
(local-host-entries): New procedure.
(operating-system-default-essential-services,
hurd-default-essential-services): Use hosts-service-type.  Use
'%operating-system-hosts-file' and 'local-host-entries'.
(default-/etc/hosts): Remove procedure.
(operating-system-etc-service): Remove hosts file.
* doc/guix.texi (operating-system Reference)
(Networking Services) (Virtualization Services): Rewrite documentation
entries to use hosts-service-type.
--8<---------------cut here---------------end--------------->8---

Thanks!
Pierre