guix package: Save provenance information when using '--manifest'.

Fixes <https://bugs.gnu.org/38673>.
Reported by zimoun <zimon.toutoune@gmail.com>.

* guix/describe.scm (manifest-entry-with-provenance): New procedure.
* guix/scripts/package.scm (process-actions): Use it when FILES is
non-empty.

guix/describe.scm

@@ -30,7 +30,8 @@
             current-profile-entries
             package-path-entries
 
-            package-provenance))
+            package-provenance
+            manifest-entry-with-provenance))
 
 ;;; Commentary:
 ;;;
@@ -144,3 +145,18 @@ property of manifest entries, or #f if it could not be determined."
                   (and main
                        `(,main
                          ,@(if extra (list extra) '()))))))))))
+
+(define (manifest-entry-with-provenance entry)
+  "Return ENTRY with an additional 'provenance' property if it's not already
+there."
+  (let ((properties (manifest-entry-properties entry)))
+    (if (assq 'properties properties)
+        entry
+        (let ((item (manifest-entry-item entry)))
+          (manifest-entry
+            (inherit entry)
+            (properties
+             (match (and (package? item) (package-provenance item))
+               (#f   properties)
+               (sexp `((provenance ,@sexp)
+                       ,@properties)))))))))

guix/scripts/package.scm

@@ -38,7 +38,7 @@
   #:use-module (guix config)
   #:use-module (guix scripts)
   #:use-module (guix scripts build)
-  #:autoload   (guix describe) (package-provenance)
+  #:use-module (guix describe)
   #:autoload   (guix store roots) (gc-roots)
   #:use-module ((guix build utils)
                 #:select (directory-exists? mkdir-p))
@@ -883,7 +883,10 @@ processed, #f otherwise."
                                  opts))
            (manifest (match files
                        (() (profile-manifest profile))
-                       (_  (concatenate-manifests (map load-manifest files)))))
+                       (_  (map-manifest-entries
+                            manifest-entry-with-provenance
+                            (concatenate-manifests
+                             (map load-manifest files))))))
            (step1    (options->removable opts manifest
                                          (manifest-transaction)))
            (step2    (options->installable opts manifest step1))