reconfigure: Use 'formatted-message'.

* guix/scripts/system/reconfigure.scm (ensure-forward-reconfigure): Use
'formatted-message'.
* guix/scripts/deploy.scm (deploy-machine*): Handle it.

guix/scripts/deploy.scm

@@ -28,6 +28,8 @@
   #:use-module (guix utils)
   #:use-module (guix grafts)
   #:use-module (guix status)
+  #:use-module (guix diagnostics)
+  #:use-module (guix i18n)
   #:use-module (ice-9 format)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
@@ -132,6 +134,13 @@ Perform the deployment specified by FILE.\n"))
             (leave (G_ "failed to deploy ~a: ~a~%")
                    (machine-display-name machine)
                    (condition-message c)))
+           ((formatted-message? c)
+            (leave (G_ "failed to deploy ~a: ~a~%")
+                   (machine-display-name machine)
+                   (apply format #f
+                          (gettext (formatted-message-string c)
+                                   %gettext-domain)
+                          (formatted-message-arguments c))))
            ((deploy-error? c)
             (when (deploy-error-should-roll-back c)
               (info (G_ "rolling back ~a...~%")

guix/scripts/system/reconfigure.scm

@@ -308,12 +308,11 @@ ancestor of COMMIT, unless CHANNEL specifies a commit."
     ('self #t)
     (_
      (raise (make-compound-condition
-             (condition
-              (&message (message
-                         (format #f (G_ "\
+             (formatted-message (G_ "\
 aborting reconfiguration because commit ~a of channel '~a' is not a descendant of ~a")
-                                 commit (channel-name channel)
-                                 start)))
+                                commit (channel-name channel)
+                                start)
+             (condition
               (&fix-hint
                (hint (G_ "Use @option{--allow-downgrades} to force
 this downgrade.")))))))))