Emacs inside container: preserved DISPLAY unavailable etc

[t]

Hi guix.

Straigt out of manual:

--------------------

$ guix shell --container --no-cwd --network emacs-next 
--expose=$HOME/.emacs.d --preserve='^DISPLAY$' -- emacs

No protocol specified
Display :1 unavailable, simulating -nw
Please set the environment variable TERM; see 'tset'.

--------------------

Why? What's going on here? Am I supposed to expose some device or 
smth? This is almost verbatim from Guix manual.

Is there a way to find out which process' reporting that error?

Lets pretend it isn't XXI century and try terminal emacs:

$ guix shell --container --no-cwd --network emacs-next 
--expose=$HOME/.emacs.d --preserve='^TERM$' -- emacs

This starts emacs in the terminal, but fails to load any user 
installed libraries e.g. use-package. Looks like they reside 
inside ~/.guix-profile/share/emacs/site-lisp, so maybe all we need 
to do is again follow the manual and --link-profile

$ guix shell --container --no-cwd --network emacs-next 
--expose=$HOME/.emacs.d --preserve='^TERM$' --link-profile -- 
emacs

That doesn't help but load-path inside emacs has 
$HOME/.guix-profile/share/emacs/site-lisp as first entry, 
hm. However, if we look inside its almost empty. So, I'm not 
entirely sure exactly what --link-profile even achieves. Is there 
some magic in play that "trims" /gnu/store entries only to 
whatever was in manifest (or packages) passed to guix shell 
--container? That would make sense if we are indeed trying to 
isolate things. If so, solution would be to -m manifest.scm with 
all my emacs packages along with emacs-next.

I'd really like to solve the 'display unavailable' above. Could 
anyone help, please?

Thank you