system: install: Always use 'current-guix'.

Fixes <https://issues.guix.gnu.org/53210>.
Reported by Mathieu Othacehe <othacehe@gnu.org>.

* gnu/system/install.scm (%installation-services): Set 'guix' to
use (current-guix) in 'guix-configuration'.
* gnu/system/examples/vm-image.tmpl: Likewise.
* gnu/tests/install.scm (operating-system-with-current-guix): Remove.
(run-install, installation-os-for-gui-tests): Remove its uses.
* Makefile.am (release): Remove intermediate use of
'update-guix-package.scm' and subsequent 'git commit' invocation.

1 files changed, 10 insertions, 4 deletions

diff --git a/gnu/system/install.scm b/gnu/system/install.scm
index a3646b1d54..32b9f52e04 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -357,11 +357,17 @@ Access documentation at any time by pressing Alt-F2.\x1b[0m
            ;; network.  It can be faster than fetching from remote servers.
            (service avahi-service-type)
 
-           ;; The build daemon.  Register the default substitute server key(s)
-           ;; as trusted to allow the installation process to use substitutes by
-           ;; default.
+           ;; The build daemon.
            (service guix-service-type
-                    (guix-configuration (authorize-key? #t)))
+                    (guix-configuration
+                     ;; Register the default substitute server key(s) as
+                     ;; trusted to allow the installation process to use
+                     ;; substitutes by default.
+                     (authorize-key? #t)
+
+                     ;; Install and run the current Guix rather than an older
+                     ;; snapshot.
+                     (guix (current-guix))))
 
            ;; Start udev so that useful device nodes are available.
            ;; Use device-mapper rules for cryptsetup & co; enable the CRDA for