linux-initrd: Use 'call-with-error-handling' when booting.

* guix/build/linux-initrd.scm (canonicalize-device-spec): When label
  resolution fails, call 'error' instead of 'format' + 'start-repl'.
  (boot-system): Wrap most of body in 'call-with-error-handling'.
  Remove 'catch' around 'primitive-load' call.

guix/build/linux-initrd.scm

@@ -20,6 +20,7 @@
   #:use-module (rnrs io ports)
   #:use-module (rnrs bytevectors)
   #:use-module (system foreign)
+  #:use-module (system repl error-handling)
   #:autoload   (system repl repl) (start-repl)
   #:autoload   (system base compile) (compile-file)
   #:use-module (srfi srfi-1)
@@ -250,10 +251,7 @@ the following:
              ;; Some devices take a bit of time to appear, most notably USB
              ;; storage devices.  Thus, wait for the device to appear.
              (if (> count max-trials)
-                 (begin
-                   (format (current-error-port)
-                           "failed to resolve partition label: ~s~%" spec)
-                   (start-repl))
+                 (error "failed to resolve partition label" spec)
                  (begin
                    (sleep 1)
                    (loop (+ 1 count))))))))
@@ -615,6 +613,8 @@ to it are lost."
   (display "Welcome, this is GNU's early boot Guile.\n")
   (display "Use '--repl' for an initrd REPL.\n\n")
 
+  (call-with-error-handling
+   (lambda ()
      (mount-essential-file-systems)
      (let* ((args    (linux-command-line))
             (to-load (find-long-option "--load" args))
@@ -676,15 +676,8 @@ to it are lost."
              (mount "none" "/dev/pts" "devpts")
 
              ;; TODO: Remove /lib, /share, and /loader.go.
-          (catch #t
-            (lambda ()
-              (primitive-load to-load))
-            (lambda args
-              (start-repl))
-            (lambda args
-              (format (current-error-port) "'~a' raised an exception: ~s~%"
-                      to-load args)
-              (display-backtrace (make-stack #t) (current-error-port))))
+             (primitive-load to-load)
+
              (format (current-error-port)
                      "boot program '~a' terminated, rebooting~%"
                      to-load)
@@ -693,6 +686,6 @@ to it are lost."
            (begin
              (display "no boot file passed via '--load'\n")
              (display "entering a warm and cozy REPL\n")
-          (start-repl)))))
+             (start-repl)))))))
 
 ;;; linux-initrd.scm ends here