Subject: Re: bug#43277: [PATCH] gnu: emacs-next: Fix load path and version

From: Morgan Smith <[email-masked]>
Date: Tue, 22 Sep 2020 09:05:51 -0400

Hello guix-devel,

I fear this patch may get lost (as it has not received feedback since I
posted it on Sept 14th (ok maybe I'm just being impatient but I'd like
to think emacs-next is an important package)) so I've decided to post it
in guix-devel. While I'm here I might as well add some much needed
information.

The emacs-next package has been broken since it was re-added on August
31st. It was added by me so this my fault. It's broken because the
EMACSLOADPATH environment variable only contains the lisp location for
your user profile and doesn't include the lisp bundled with
emacs-next. If you have emacs and emacs-next installed at the same time,
emacs-next appears to work as expected because it's using the lisp
installed with emacs. I'm not sure if there is a way to make sure people
only install emacs or emacs-next, but you should only install one.

I created the below patch on Sept 14th, and have been using it daily
since then with no issues.

The version goes from 28.0.50.1 to 28.0.50. The "1" is the build number
which gets incremented every time you run "make" (so not actually part
of the version). Also it's important to get the version correct as I use
it to refer to the binary.

When we copy the binary in 'string-double-wrap, I've decided to just
string split on #\-. This is remove the end of the git-version string so
we're left with just 28.0.50.

I need to copy the native-search-paths section from emacs and place it
into emacs-next. It would be cooler if the native-search-paths sections
was thunked so I could pull the this-package trick again to get the
right version, but I think this is the only way.

Thanks,

Morgan

[email-masked] writes:

> From: Morgan Smith <[email-masked]>
>
> * gnu/packages/emacs.scm (emacs):
> [strip-double-wrap] Modify to work with emacs-next
>
> * gnu/packages/emacs.scm (emacs-next):
> [version] Change version from 28.0.50.1 to 28.0.50
> [arguments] Removed field
> [native-search-paths] New field
> ---
>
> The problem turned out to be that EMACSLOADPATH wasn't being set
> properly.  This patch fixes that.
>
>
>
>  gnu/packages/emacs.scm | 37 ++++++++++++++++---------------------
>  1 file changed, 16 insertions(+), 21 deletions(-)
>
> diff --git a/gnu/packages/emacs.scm b/gnu/packages/emacs.scm
> index 03c28ee7a7..b3d099257d 100644
> --- a/gnu/packages/emacs.scm
> +++ b/gnu/packages/emacs.scm
> @@ -196,11 +196,12 @@
>             (lambda* (#:key outputs #:allow-other-keys)
>               ;; Directly copy emacs-X.Y to emacs, so that it is not wrapped
>               ;; twice.  This also fixes a minor issue, where WMs would not be
> -             ;; able to track emacs back to emacs.desktop.
> +             ;; able to track emacs back to emacs.desktop.  It's done using
> +             ;; this-package so emacs-next can reuse it
>               (with-directory-excursion (assoc-ref outputs "out")
>                 (copy-file (string-append
>                             "bin/emacs-"
> -                           ,(version-major+minor (package-version emacs)))
> +                           ,(car (string-split (package-version this-package) #\-)))
>                            "bin/emacs")
>                 #t)))
>           (add-before 'reset-gzip-timestamps 'make-compressed-files-writable
> @@ -279,11 +280,10 @@ languages.")
>  
>  (define-public emacs-next
>    (let ((commit "2ea34662c20f71d35dd52a5ed996542c7386b9cb")
> -        (revision "0")
> -        (emacs-version "28.0.50.1"))
> +        (revision "0"))
>      (package/inherit emacs
>        (name "emacs-next")
> -      (version (git-version emacs-version revision commit))
> +      (version (git-version "28.0.50" revision commit))
>        (source
>         (origin
>           (inherit (package-source emacs))
> @@ -295,24 +295,19 @@ languages.")
>           (sha256
>            (base32
>             "0igjm9kwiswn2dpiy2k9xikbdfc7njs07ry48fqz70anljj8y7y3"))))
> -      (arguments
> -       (substitute-keyword-arguments (package-arguments emacs)
> -         ((#:phases phases)
> -          `(modify-phases ,phases
> -             (replace 'strip-double-wrap
> -               (lambda* (#:key outputs #:allow-other-keys)
> -                 ;; Directly copy emacs-X.Y to emacs, so that it is not wrapped
> -                 ;; twice.  This also fixes a minor issue, where WMs would not be
> -                 ;; able to track emacs back to emacs.desktop.
> -                 (with-directory-excursion (assoc-ref outputs "out")
> -                   (copy-file (string-append
> -                               "bin/emacs-"
> -                               ,(version-major+minor+point (package-version emacs-next)))
> -                              "bin/emacs")
> -                   #t)))))))
>        (native-inputs
>         `(("autoconf" ,autoconf)
> -         ,@(package-native-inputs emacs))))))
> +         ,@(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/" (car (string-split version #\-)) "/lisp"))))
> +             (search-path-specification
> +              (variable "INFOPATH")
> +              (files '("share/info"))))))))
>  
>  (define-public emacs-minimal
>    ;; This is the version that you should use as an input to packages that just