Hi,

I recently got the following error message from "guix home build" 
(misleading it says "warning" instead):

> warning: collision encountered:
>   /gnu/store/xjrhyapm3zwgpmq5baz6m9kavz287jjj-emacs-29.1/share/info/transient.info.gz
>   /gnu/store/lg6h2mkg5z15i78dzvzs0s89bgxxwnlf-emacs-transient-0.4.3-0.cc0fa80/share/info/transient.info.gz
> warning: choosing /gnu/store/xjrhyapm3zwgpmq5baz6m9kavz287jjj-emacs-29.1/share/info/transient.info.gz

Unfortunately, the following doesn't work as minimal reproducer, because 
"guix shell" (and likewise for "environment") suppresses collision error 
messages:

$ guix shell emacs emacs-transient

(see: https://issues.guix.gnu.org/54350).

(That's not what this bug report is about.)

Bug 1: emacs bundles emacs-transient.
(Likewise for quite a few other Emacs packages.)

Bug 2: no collision handling.

If I'm guessing correctly, emacs-transient is supposed to be a newer 
version of the transient bundled in emacs, overriding the bundled 
transient in emacs.  But for that to work properly, it needs to actually 
override the stuff, and going by the collision error message, it isn't 
actually overridden but rather the profile building code arbitrarily 
chooses between the two.

I guess (guix profiles) should set #:resolve-collision to something 
where the "[...]/transient.info.gz" of the store item containing 
"[...]/bin/emacs" loses.  (And likewise for the other bundled Emacs stuff.)

Best regards,
Maxime Devos