Ludovic Courtès (2015-10-16 11:20 +0300) wrote:

> Alex Kost <alezost@gmail.com> skribis:
>
>> What about modifying ‘guix’ package to make various "View graph" actions
>> in "M-x guix" work by default (without installing graphviz)?
>
> I would rather change Guix itself: What about adding ‘guix-dot-program’
> to guix-config.el.in, set to "@DOT_USER_PROGRAM@" (which doesn’t exist
> yet)?

Great idea!  However I think instead of moving ‘guix-dot-program’ to
"guix-config.el.in", it is better to move ‘guix-guile-program’ to
"guix-external.el" instead (explained below).

> We can’t use @DOT@ because currently it is set to something like:
>
>   DOT='${SHELL} /home/ludo/src/guix/build-aux/missing dot'

Yes, that's why I didn't use @DOT@, and decided to modify the ‘guix’
package instead.

> So we need an AC_PATH_PROG for dot that defines the ‘DOT_USER_PROGRAM’
> substitution variable.
>
> Does that make sense?

Yes, this is great!  I didn't think to go this way, thanks!

Along with the patch for this change, I'm also attaching a patch to
"improve" guix-config.el: to make all its constants begin with
"guix-config-" prefix and to use them in the real variables that may be
modified by a user.  WDYT?