emacsclient cannot open display

[crawford]

Describe the bug

I have the Emacs daemon enabled on my system (services.emacs.enable = true;). When I log in, I can see that the daemon is running but I am unable to start emacsclient:

$ emacsclient -c
Waiting for Emacs...
*ERROR*: Display :0 can’t be opened

Restarting the daemon fixes the issue. Is the daemon starting too early and missing some variables from Wayland?

Steps To Reproduce

Steps to reproduce the behavior:

1. Enable emacs daemon (services.emacs.enable = true;)
2. Log in and try to run emacsclient

Expected behavior

emacsclient starts:

$ emacsclient -c
Waiting for Emacs...

Notify maintainers

@DamienCassou

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 5.15.103, NixOS, 22.11 (Raccoon), 22.11.3265.e2c97799da5`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.11.1`
 - channels(root): `"machines, nixos-22.11, nixos-hardware"`
 - channels(alex): `""`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

[DamienCassou]

I'm not the maintainer of this service and I don't use it. I use the Emacs service from home-manager which I recommend: https://rycee.gitlab.io/home-manager/.

[crawford]

My apologies. I saw that you were the original author, so I figured you were my best bet.

It looks like home-manager might be avoiding this by (optionally) using socket activation. Something similar might work here, but I'm sure there's a more robust solution. I'll have to dig into it a bit when I have time.

[DamienCassou]

Does nix-community/home-manager#3443 (comment) helps @crawford?

[crawford]

Yeah, ordering emacs.service after graphical-session.target seems to have worked. Thanks for the tip. I'm trying to work up a nice way to incorporate that into the service definition. Unfortunately, simply adding the "after" directive doesn't seem to be enough. I'm guessing that's because default.target is reached, or at least initiated, before graphical-session.target. I'm going to keep poking at it over the coming days.

[ibizaman]

Wanted to confirm startWithUserSession = "graphical" made this issue go away.

[jys1670]

Same here, "graphical" solution works. It would be nice to see @Atemu's pr merged.