Re: guix pull package output truncated

[Ludovic Courtès]

Howdy!

Tobias Geerinckx-Rice <address@hidden> skribis:

> Ludovic Courtès wrote:
>> There’s currently no flag to change this behavior.  Instead, you
>> have to
>> run ‘guix pull -l’ but it’s arguably not very convenient.
>>
>> Perhaps we could add an environment variable specifying whether/how
>> to
>> truncate?  I’d keep the default as it is now.
>
> AIUC, this list of changes is displayed once and then ‘lost’ (to the
> average user) when they clear their screen, right?

Yup.

> Or is there a command that returns this nice list of differences
> between two guix-profiles that we could suggest running when the
> default is truncated?  It could default to current and current-1, and
> would solve both (minor) irritations.

I think that’s a good idea.

What about a ‘--news’ option along with a hint as in the attached patch?

--8<---------------cut here---------------start------------->8---
$ guix pull --news
New in this revision:
  9 new packages: cl-log4cl, ecl-log4cl, emacs-ace-jump-mode, emacs-ace-link, 
libomp, lucene++,
    mate-power-manager, poedit, sbcl-log4cl
  63 packages upgraded: address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden, address@hidden,
    address@hidden, address@hidden, address@hidden, address@hidden, 
address@hidden,
    address@hidden
--8<---------------cut here---------------end--------------->8---

I’ll push it with documentation if there are no objections.

Thanks!

Ludo’.

diff --git a/guix/scripts/pull.scm b/guix/scripts/pull.scm
index 71e13686c0..fe6ebb1656 100644
--- a/guix/scripts/pull.scm
+++ b/guix/scripts/pull.scm
@@ -117,6 +117,9 @@ Download and deploy the latest version of Guix.\n"))
                  (lambda (opt name arg result)
                    (cons `(query list-generations ,(or arg ""))
                          result)))
+         (option '(#\N "news") #f #f
+                 (lambda (opt name arg result)
+                   (cons '(query display-news) result)))
          (option '("url") #t #f
                  (lambda (opt name arg result)
                    (alist-cons 'repository-url arg
@@ -162,25 +165,28 @@ Download and deploy the latest version of Guix.\n"))
 (define indirect-root-added
   (store-lift add-indirect-root))
 
-(define (display-profile-news profile)
+(define* (display-profile-news profile #:key concise?
+                               current-is-newer?)
   "Display what's up in PROFILE--new packages, and all that."
   (match (memv (generation-number profile)
                (reverse (profile-generations profile)))
     ((current previous _ ...)
-     (newline)
-     (let ((old (fold-available-packages
-                 (lambda* (name version result
-                                #:key supported? deprecated?
-                                #:allow-other-keys)
-                   (if (and supported? (not deprecated?))
-                       (alist-cons name version result)
-                       result))
-                 '()))
-           (new (profile-package-alist
-                 (generation-file-name profile current))))
-       (display-new/upgraded-packages old new
-                                      #:concise? #t
-                                      #:heading (G_ "New in this 
revision:\n"))))
+     (let ((these (fold-available-packages
+                   (lambda* (name version result
+                                  #:key supported? deprecated?
+                                  #:allow-other-keys)
+                     (if (and supported? (not deprecated?))
+                         (alist-cons name version result)
+                         result))
+                   '()))
+           (those (profile-package-alist
+                   (generation-file-name profile current))))
+       (let ((old (if current-is-newer? those these))
+             (new (if current-is-newer? these those)))
+         (display-new/upgraded-packages old new
+                                        #:concise? concise?
+                                        #:heading
+                                        (G_ "New in this revision:\n")))))
     (_ #t)))
 
 (define* (build-and-install instances profile
@@ -196,7 +202,8 @@ true, display what would be built without actually building 
it."
                       #:hooks %channel-profile-hooks
                       #:dry-run? dry-run?)
       (munless dry-run?
-        (return (display-profile-news profile))
+        (return (newline))
+        (return (display-profile-news profile #:concise? #t))
         (match (which "guix")
           (#f (return #f))
           (str
@@ -394,9 +401,13 @@ display long package lists that would fill the user's 
screen."
                                      column)
                      4))
 
+  (define concise/max-item-count
+    ;; Maximum number of items to display when CONCISE? is true.
+    12)
+
   (define list->enumeration
     (if concise?
-        (lambda* (lst #:optional (max 12))
+        (lambda* (lst #:optional (max concise/max-item-count))
           (if (> (length lst) max)
               (string-append (string-join (take lst max) ", ")
                              ", " (ellipsis))
@@ -404,10 +415,13 @@ display long package lists that would fill the user's 
screen."
         (cut string-join <> ", ")))
 
   (let-values (((new upgraded) (new/upgraded-packages alist1 alist2)))
+    (define new-count (length new))
+    (define upgraded-count (length upgraded))
+
     (unless (and (null? new) (null? upgraded))
       (display heading))
 
-    (match (length new)
+    (match new-count
       (0 #t)
       (count
        (format #t (N_ "  ~h new package: ~a~%"
@@ -415,14 +429,20 @@ display long package lists that would fill the user's 
screen."
                count
                (pretty (list->enumeration (sort (map first new) string<?))
                        30))))
-    (match (length upgraded)
+    (match upgraded-count
       (0 #t)
       (count
        (format #t (N_ "  ~h package upgraded: ~a~%"
                       "  ~h packages upgraded: ~a~%" count)
                count
                (pretty (list->enumeration (sort upgraded string<?))
-                       35))))))
+                       35))))
+
+    (when (and concise?
+               (or (> new-count concise/max-item-count)
+                   (> upgraded-count concise/max-item-count)))
+      (display-hint (G_ "Run @command{guix pull --news} to view the complete
+list of package changes.")))))
 
 (define (display-profile-content-diff profile gen1 gen2)
   "Display the changes in PROFILE GEN2 compared to generation GEN1."
@@ -462,7 +482,12 @@ display long package lists that would fill the user's 
screen."
                (()
                 (exit 1))
                ((numbers ...)
-                (list-generations profile numbers)))))))))
+                (list-generations profile numbers)))))))
+    (('display-news)
+     ;; Display profile news, with the understanding that this process
+     ;; represents the newest generation.
+     (display-profile-news profile
+                           #:current-is-newer? #t))))
 
 (define (channel-list opts)
   "Return the list of channels to use.  If OPTS specify a channel file,