emacs: Display supported systems in "Package Info".

* emacs/guix-main.scm (%package-param-alist): Add 'systems'.
* emacs/guix-ui-package.el (guix-package-info-insert-systems): New
  procedure.
  (guix-package-info-format): Add it.
  (guix-output-info-format): Likewise.
  (guix-package-info-titles): Add "Supported systems" title.

2 files changed, 19 insertions, 1 deletions

diff --git a/emacs/guix-main.scm b/emacs/guix-main.scm
index 6f9eb422e0..8c38e7cae3 100644
--- a/emacs/guix-main.scm
+++ b/emacs/guix-main.scm
@@ -307,6 +307,7 @@ Example:
     (description       . ,package-description-string)
     (home-url          . ,package-home-page)
     (outputs           . ,package-outputs)
+    (systems           . ,package-supported-systems)
     (non-unique        . ,(negate package-unique?))
     (inputs            . ,(lambda (pkg)
                             (package-inputs-names
diff --git a/emacs/guix-ui-package.el b/emacs/guix-ui-package.el
index e0c98eaed6..12bfaeef68 100644
--- a/emacs/guix-ui-package.el
+++ b/emacs/guix-ui-package.el
@@ -221,11 +221,13 @@ ENTRIES is a list of package entries to get info about packages."
             (location format (format guix-package-location))
             (home-url format (format guix-url))
             (license format (format guix-package-info-license))
+            (systems format guix-package-info-insert-systems)
             (inputs format (format guix-package-input))
             (native-inputs format (format guix-package-native-input))
             (propagated-inputs format
                                (format guix-package-propagated-input)))
-  :titles '((home-url . "Home page"))
+  :titles '((home-url . "Home page")
+            (systems . "Supported systems"))
   :required '(id name version installed non-unique))
 
 (guix-info-define-interface installed-output
@@ -363,6 +365,20 @@ formatted with this string, an action button is inserted.")
    'guix-package-name
    'face 'guix-package-info-heading))
 
+(defun guix-package-info-insert-systems (systems entry)
+  "Insert supported package SYSTEMS at point."
+  (guix-info-insert-value-format
+   systems 'guix-hydra-build-system
+   'action (lambda (btn)
+             (let ((args (guix-hydra-build-latest-prompt-args
+                          :job (button-get btn 'job-name)
+                          :system (button-label btn))))
+               (apply #'guix-hydra-build-get-display
+                      'latest args)))
+   'job-name (guix-package-name-specification
+              (guix-entry-value entry 'name)
+              (guix-entry-value entry 'version))))
+
 (defmacro guix-package-info-define-insert-inputs (&optional type)
   "Define a face and a function for inserting package inputs.
 TYPE is a type of inputs.
@@ -749,6 +765,7 @@ for all ARGS."
             (location format (format guix-package-location))
             (home-url format (format guix-url))
             (license format (format guix-package-info-license))
+            (systems format guix-package-info-insert-systems)
             (inputs format (format guix-package-input))
             (native-inputs format (format guix-package-native-input))
             (propagated-inputs format