command-line-tool: Bubble up manifest file errors to the top level.HEADmain

* ravanan/command-line-tool.scm: Import (rnrs conditions) and (rnrs
exceptions).
(&manifest-file-error): New condition type.
(load-manifest): Raise &manifest-file-error when loading the manifest
file fails.
* bin/ravanan: Import (rnrs exceptions) and (ravanan
command-line-tool).
(main): Handle manifest file errors bubbled up from lower down the
stack.

2 files changed, 79 insertions, 39 deletions

diff --git a/bin/ravanan b/bin/ravanan
index 37d10df..f8fcdf8 100755
--- a/bin/ravanan
+++ b/bin/ravanan
@@ -20,7 +20,8 @@ exec guile --no-auto-compile -e main -s "$0" "$@"
 ;;; You should have received a copy of the GNU General Public License
 ;;; along with ravanan.  If not, see <https://www.gnu.org/licenses/>.
 
-(use-modules (rnrs io ports)
+(use-modules (rnrs exceptions)
+             (rnrs io ports)
              (srfi srfi-26)
              (srfi srfi-37)
              (ice-9 filesystem)
@@ -28,6 +29,7 @@ exec guile --no-auto-compile -e main -s "$0" "$@"
              (web uri)
              (json)
              (ravanan batch-system)
+             (ravanan command-line-tool)
              (ravanan reader)
              (ravanan utils)
              (ravanan workflow))
@@ -142,38 +144,57 @@ files that have the token in the @verbatim{SLURM_JWT=token} format."
          ((workflow-file inputs-file)
           ;; We must not try to compile guix manifest files.
           (set! %load-should-auto-compile #f)
-          (scm->json (run-workflow (file-name-stem workflow-file)
-                                   (canonicalize-path
-                                    (assq-ref args 'guix-manifest-file))
-                                   (and (assq-ref args 'guix-channels-file)
-                                        (load-script
-                                         (canonicalize-path
-                                          (assq-ref args 'guix-channels-file))
-                                         #:modules '((guile)
-                                                     (guix channels))))
-                                   (read-workflow workflow-file)
-                                   (read-inputs inputs-file)
-                                   (case (assq-ref args 'batch-system)
-                                     ((single-machine)
-                                      (or (assq-ref args 'scratch)
-                                          (getcwd)))
-                                     ((slurm-api)
-                                      (assq-ref args 'scratch)))
-                                   ;; FIXME: This is a bit of a hack to
-                                   ;; avoid canonizing remote paths.
-                                   (if (file-name-absolute? (assq-ref args 'store))
-                                       (assq-ref args 'store)
-                                       (canonicalize-path (assq-ref args 'store)))
-                                   (case (assq-ref args 'batch-system)
-                                     ((single-machine) 'single-machine)
-                                     ((slurm-api)
-                                      (slurm-api-batch-system
-                                       (assq-ref args 'slurm-api-endpoint)
-                                       (and (assq-ref args 'slurm-jwt)
-                                            (read-jwt (assq-ref args 'slurm-jwt)))
-                                       (assq-ref args 'slurm-partition)
-                                       (assq-ref args 'slurm-nice))))
-                                   #:guix-daemon-socket (assq-ref args 'guix-daemon-socket))
+          (scm->json (guard (c ((manifest-file-error? c)
+                                ;; Steps may provide their own
+                                ;; SoftwareRequirement. So, at this point, we do
+                                ;; not know if a manifest file is required and
+                                ;; can't check for these manifest file errors
+                                ;; right away. Instead, we depend on exceptions
+                                ;; bubbled up from lower down the stack.
+                                (let ((file (manifest-file-error-file c)))
+                                  (cond
+                                   ((not file)
+                                    (error "--guix-manifest not specified"))
+                                   ((not (file-exists? file))
+                                    (error "Manifest file ~a does not exist"
+                                           file))
+                                   (else
+                                    (error "Error loading manifest file"
+                                           file)
+                                    (raise-exception c))))))
+                       (run-workflow (file-name-stem workflow-file)
+                                     (and (assq 'guix-manifest-file args)
+                                          (canonicalize-path
+                                           (assq-ref args 'guix-manifest-file)))
+                                     (and (assq-ref args 'guix-channels-file)
+                                          (load-script
+                                           (canonicalize-path
+                                            (assq-ref args 'guix-channels-file))
+                                           #:modules '((guile)
+                                                       (guix channels))))
+                                     (read-workflow workflow-file)
+                                     (read-inputs inputs-file)
+                                     (case (assq-ref args 'batch-system)
+                                       ((single-machine)
+                                        (or (assq-ref args 'scratch)
+                                            (getcwd)))
+                                       ((slurm-api)
+                                        (assq-ref args 'scratch)))
+                                     ;; FIXME: This is a bit of a hack to
+                                     ;; avoid canonizing remote paths.
+                                     (if (file-name-absolute? (assq-ref args 'store))
+                                         (assq-ref args 'store)
+                                         (canonicalize-path (assq-ref args 'store)))
+                                     (case (assq-ref args 'batch-system)
+                                       ((single-machine) 'single-machine)
+                                       ((slurm-api)
+                                        (slurm-api-batch-system
+                                         (assq-ref args 'slurm-api-endpoint)
+                                         (and (assq-ref args 'slurm-jwt)
+                                              (read-jwt (assq-ref args 'slurm-jwt)))
+                                         (assq-ref args 'slurm-partition)
+                                         (assq-ref args 'slurm-nice))))
+                                     #:guix-daemon-socket (assq-ref args 'guix-daemon-socket)))
                      (current-output-port)
                      #:pretty #t)
           (newline (current-output-port))))))))
diff --git a/ravanan/command-line-tool.scm b/ravanan/command-line-tool.scm
index ca78e4c..096968c 100644
--- a/ravanan/command-line-tool.scm
+++ b/ravanan/command-line-tool.scm
@@ -18,6 +18,8 @@
 
 (define-module (ravanan command-line-tool)
   #:use-module ((rnrs base) #:select (assertion-violation error))
+  #:use-module (rnrs conditions)
+  #:use-module (rnrs exceptions)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-9 gnu)
   #:use-module (srfi srfi-26)
@@ -60,7 +62,16 @@
 
             %store-files-directory
             %store-data-directory
-            %store-logs-directory))
+            %store-logs-directory
+
+            manifest-file-error?
+            manifest-file-error-file))
+
+;; &manifest-file-error represents an error loading an user-provided manifest
+;; file.
+(define-condition-type &manifest-file-error &error
+  manifest-file-error manifest-file-error?
+  (file manifest-file-error-file))
 
 (define %store-files-directory
   "files")
@@ -556,11 +567,19 @@ maybe-monadic value."
 
 (define (load-manifest manifest-file)
   "Load Guix manifest from @var{manifest-file} and return it."
-  (load-script manifest-file
-               #:modules '((guile)
-                           (gnu packages)
-                           (guix gexp)
-                           (guix profiles))))
+  (if (and manifest-file
+           (file-exists? manifest-file))
+      ;; Capture conditions raised by load-script and bubble them up along with
+      ;; &manifest-file-error.
+      (guard (c (else
+                 (raise-exception (condition (manifest-file-error manifest-file)
+                                             c))))
+        (load-script manifest-file
+                     #:modules '((guile)
+                                 (gnu packages)
+                                 (guix gexp)
+                                 (guix profiles))))
+      (raise-exception (manifest-file-error manifest-file))))
 
 (define (call-with-inferior inferior proc)
   "Call @var{proc} with @var{inferior} and return the return value of @var{proc}.