bug#47458: Terrible UX upgrading Emacs in Guix

[Maxim Cournoyer]

Hi Leo!

Leo Prikler <leo.prikler@student.tugraz.at> writes:

> With this, the search path specification of EMACSLOADPATH does no longer
> depend on the version of Emacs, which should make upgrading major versions
> less painful.  See also:
> - <https://bugs.gnu.org/43627>
> - <https://bugs.gnu.org/47458>
>
> * gnu/packages/emacs.scm (emacs)[#:phases]: Add ‘wrap-load-path’.
> [native-search-path]<EMACSLOADPATH>: Do not search for builtin libraries.
> (emacs-next)[native-search-path]: Inherit from emacs.
> ---
>  gnu/packages/emacs.scm | 31 ++++++++++++++++---------------
>  1 file changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/gnu/packages/emacs.scm b/gnu/packages/emacs.scm
> index 7447cfe33a..e12c489f8d 100644
> --- a/gnu/packages/emacs.scm
> +++ b/gnu/packages/emacs.scm
> @@ -201,6 +201,20 @@
>                  (car (find-files "bin" "^emacs-([0-9]+\\.)+[0-9]+$"))
>                  "bin/emacs")
>                 #t)))
> +         (add-after 'strip-double-wrap 'wrap-load-path
> +           (lambda* (#:key outputs #:allow-other-keys)
> +             (let* ((out (assoc-ref outputs "out"))
> +                    (lisp-dirs (find-files (string-append out "/share/emacs")
> +                                           "^lisp$"
> +                                           #:directories? #t)))
> +               (for-each
> +                (lambda (prog)
> +                  (wrap-program prog
> +                    `("EMACSLOADPATH" suffix ,lisp-dirs)))
> +                (find-files (string-append out "/bin")
> +                            ;; versioned and unversioned emacs binaries
> +                            "^emacs(-[0-9]+(\\.[0-9]+)*)?$"))
> +               #t)))

Shouldn't we wrap all the binaries to be on the safe side?  Things such
as emacsclient probably ought to have EMACSLOADPATH set correctly, no?

>           (add-before 'reset-gzip-timestamps 'make-compressed-files-writable
>             ;; The 'reset-gzip-timestamps phase will throw a permission error
>             ;; if gzip files aren't writable then.  This phase is needed when
> @@ -255,9 +269,7 @@
>      (native-search-paths
>       (list (search-path-specification
>              (variable "EMACSLOADPATH")
> -            ;; The versioned entry is for the Emacs' builtin libraries.
> -            (files (list "share/emacs/site-lisp"
> -                         (string-append "share/emacs/" version "/lisp"))))
> +            (files '("share/emacs/site-lisp")))
>             (search-path-specification
>              (variable "INFOPATH")
>              (files '("share/info")))))
> @@ -294,18 +306,7 @@ languages.")
>             "0igjm9kwiswn2dpiy2k9xikbdfc7njs07ry48fqz70anljj8y7y3"))))
>        (native-inputs
>         `(("autoconf" ,autoconf)
> -         ,@(package-native-inputs emacs)))
> -      (native-search-paths
> -       (list (search-path-specification
> -              (variable "EMACSLOADPATH")
> -              ;; The versioned entry is for the Emacs' builtin libraries.
> -              (files (list "share/emacs/site-lisp"
> -                           (string-append "share/emacs/"
> -                                          (version-major+minor+point version)
> -                                          "/lisp"))))
> -             (search-path-specification
> -              (variable "INFOPATH")
> -              (files '("share/info"))))))))
> +         ,@(package-native-inputs emacs))))))
>  
>  (define-public emacs-next-pgtk
>    (let ((commit "ae18c8ec4f0ef37c8c9cda473770ff47e41291e2")

This makes sense, and can make it to master rather than core-updates,
which is neat.

Thank you :-)

Maxim