images: wsl2: Make the dummy bootloader configuration lowerable.

"guix system reconfigure" lowers the bootloader configuration
and then calls 'derivation->output-path' on the result.  A 'plain-file'
lowers to a store file name rather than to a derivation,
so reconfiguring a WSL2 system fails with "Wrong type argument
in position 1 (expecting struct)".  Use 'computed-file',
which lowers to a derivation.

* gnu/system/images/wsl2.scm (dummy-bootloader)
  [configuration-file-generator]: Return a 'computed-file'
  instead of a 'plain-file'.

Merges: https://codeberg.org/guix/guix/pulls/10514
Reviewed-by: gemmaro <gemmaro.dev@gmail.com>
Signed-off-by: Nguyễn Gia Phong <cnx@loang.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/gnu/system/images/wsl2.scm b/gnu/system/images/wsl2.scm
index ce58cd55c60..8729fc45396 100644
--- a/gnu/system/images/wsl2.scm
+++ b/gnu/system/images/wsl2.scm
@@ -134,7 +134,9 @@ USER."
    (configuration-file "/var/lib/wsl-bootloader.cfg")
    (configuration-file-generator
     (lambda (. _rest)
-      (plain-file "dummy-bootloader" "")))
+      (computed-file "dummy-bootloader"
+                     #~(call-with-output-file #$output
+                         (lambda (port) (display "" port))))))
    (installer #~(const #t))))
 
 (define dummy-kernel dummy-package)