services: boot: Take gexps instead of monadic gexps.

* gnu/services.scm (compute-boot-script): Rename 'mexps' to 'gexps' and
remove 'mlet' form.
(boot-service-type): Update comment.
(cleanup-gexp): Remove 'with-monad' and 'return'.
(activation-script): Rewrite in non-monadic style: use 'scheme-file'
instead of 'gexp->file'.
(gexps->activation-gexp): Remove 'mlet', return a gexp.
* gnu/services/shepherd.scm (shepherd-boot-gexp): Remove 'with-monad'
and 'return'.
* gnu/system.scm (operating-system-boot-script): Remove outdated comment.
* gnu/tests/base.scm (%cleanup-os): For 'dirty-service', remove
'with-monad' and 'return'.

1 files changed, 19 insertions, 21 deletions

diff --git a/gnu/services/shepherd.scm b/gnu/services/shepherd.scm
index 000e85eb86..6ca53faa3d 100644
--- a/gnu/services/shepherd.scm
+++ b/gnu/services/shepherd.scm
@@ -22,7 +22,6 @@
   #:use-module (guix sets)
   #:use-module (guix gexp)
   #:use-module (guix store)
-  #:use-module (guix monads)
   #:use-module (guix records)
   #:use-module (guix derivations)                 ;imported-modules, etc.
   #:use-module (gnu services)
@@ -66,26 +65,25 @@
 
 
 (define (shepherd-boot-gexp services)
-  (with-monad %store-monad
-    (return #~(begin
-                ;; Keep track of the booted system.
-                (false-if-exception (delete-file "/run/booted-system"))
-                (symlink (readlink "/run/current-system")
-                         "/run/booted-system")
-
-                ;; Close any remaining open file descriptors to be on the safe
-                ;; side.  This must be the very last thing we do, because
-                ;; Guile has internal FDs such as 'sleep_pipe' that need to be
-                ;; alive.
-                (let loop ((fd 3))
-                  (when (< fd 1024)
-                    (false-if-exception (close-fdes fd))
-                    (loop (+ 1 fd))))
-
-                ;; Start shepherd.
-                (execl #$(file-append shepherd "/bin/shepherd")
-                       "shepherd" "--config"
-                       #$(shepherd-configuration-file services))))))
+  #~(begin
+      ;; Keep track of the booted system.
+      (false-if-exception (delete-file "/run/booted-system"))
+      (symlink (readlink "/run/current-system")
+               "/run/booted-system")
+
+      ;; Close any remaining open file descriptors to be on the safe
+      ;; side.  This must be the very last thing we do, because
+      ;; Guile has internal FDs such as 'sleep_pipe' that need to be
+      ;; alive.
+      (let loop ((fd 3))
+        (when (< fd 1024)
+          (false-if-exception (close-fdes fd))
+          (loop (+ 1 fd))))
+
+      ;; Start shepherd.
+      (execl #$(file-append shepherd "/bin/shepherd")
+             "shepherd" "--config"
+             #$(shepherd-configuration-file services))))
 
 (define shepherd-root-service-type
   (service-type