gnu: Add %dummy-linux-kernel-for-container.

* gnu/packages/linux.scm (%dummy-linux-kernel-for-container): New variable.
* gnu/system/linux-container.scm (containerized-operating-system): Use it.

Change-Id: Ica49a0cd0b8ae4a78ba5fca879ae73f94e64474a

gnu/packages/linux.scm

@@ -1231,6 +1231,25 @@ Linux kernel.  It has been modified to remove all non-free binary blobs.")
 ;;; Specialized kernel variants.
 ;;;
 
+(define-public %dummy-linux-kernel-for-container
+  (hidden-package
+   (package
+     (name "linux-dummy")
+     (version "0.0.0")
+     (source #f)
+     (build-system copy-build-system)
+     (arguments
+      (list #:phases
+            #~(modify-phases %standard-phases
+                (delete 'unpack)
+                (replace 'install
+                  (lambda _
+                    (mkdir-p #$output))))))
+     (home-page "")
+     (synopsis "Dummy Linux kernel for @command{guix system container}")
+     (description "")
+     (license #f))))
+
 (define-public linux-libre-arm-generic
   (make-linux-libre* linux-libre-version
                      linux-libre-gnu-revision

gnu/system/linux-container.scm

@@ -40,6 +40,7 @@
   #:use-module (gnu services shepherd)
   #:use-module (gnu system)
   #:use-module (gnu system file-systems)
+  #:use-module (gnu packages linux)
   #:export (system-container
             containerized-operating-system
             container-script
@@ -152,6 +153,7 @@ containerized OS.  EXTRA-FILE-SYSTEMS is a list of file systems to add to OS."
   (define os-with-base-essential-services
     (operating-system
       (inherit os)
+      (kernel %dummy-linux-kernel-for-container)
       (swap-devices '()) ; disable swap
       (services
        (append services-to-add