103/197: installer: Avoid exception when the device to format cannot be found.

[Danny Milosavljevic]

dannym pushed a commit to branch wip-installer-2
in repository guix.

commit 1a0f4e6cc3d56caede4059674b590ba99dc0b974
Author: John Darrington <address@hidden>
Date:   Sun Jan 15 16:56:21 2017 +0100

    installer: Avoid exception when the device to format cannot be found.
    
    * gnu/system/installer/format.scm (device-fs-uuid): Add a catch-all case.
---
 gnu/system/installer/format.scm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gnu/system/installer/format.scm b/gnu/system/installer/format.scm
index 81483cf..1f32196 100644
--- a/gnu/system/installer/format.scm
+++ b/gnu/system/installer/format.scm
@@ -44,7 +44,8 @@ device such as /dev/sda1"
                    (string-split x #\=))) "UUID")
          (() #f)
          ((? list? l)
-          (car l))))
+          (car l))
+         (_ #f)))
 
 (define (filesystems-are-current?)
   "Returns #t iff there is at least one mount point AND all mount-points' uuids