From e871c3a857005c2c55fcbf4dbd48e22fe33b6451 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Fri, 1 Jul 2022 09:42:53 +0200
Subject: [PATCH] image: 'system-image' throws when given an incorrect image
 format.

Previously 'system-image' would return *unspecified* in that case,
leading to a wrong-type-arg error crash down the road.

* gnu/system/image.scm (system-image): Add 'else' clause.
---
 gnu/system/image.scm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gnu/system/image.scm b/gnu/system/image.scm
index 5972a944d7..f1739a35c1 100644
--- a/gnu/system/image.scm
+++ b/gnu/system/image.scm
@@ -842,7 +842,10 @@ (define target (cond
           ;; This happens if some limits are exceeded, see:
           ;; https://lists.gnu.org/archive/html/grub-devel/2020-06/msg00048.html
           #:grub-mkrescue-environment
-          '(("MKRESCUE_SED_MODE" . "mbr_only"))))))))
+          '(("MKRESCUE_SED_MODE" . "mbr_only"))))
+       (else
+        (raise (formatted-message
+                (G_ "~a: unsupported image format") image-format)))))))
 
 
 ;;