nixos/emacs: start emacs service with the graphical-session

If emacs starts before the graphical session is initialised, clients won't be
able to open new frames in the session. Start emacs with the graphical session
to avoid this issue.

Fixes https://github.com/NixOS/nixpkgs/issues/224512

1 files changed, 16 insertions, 1 deletions

diff --git a/nixos/modules/services/editors/emacs.nix b/nixos/modules/services/editors/emacs.nix
index fe3a101597947..fad4f39ff2104 100644
--- a/nixos/modules/services/editors/emacs.nix
+++ b/nixos/modules/services/editors/emacs.nix
@@ -80,6 +80,15 @@ in
         using the EDITOR environment variable.
       '';
     };
+
+    startWithGraphical = mkOption {
+      type = types.bool;
+      default = config.services.xserver.enable;
+      defaultText = literalExpression "config.services.xserver.enable";
+      description = lib.mdDoc ''
+        Start emacs with the graphical session instead of any session. Without this, emacs clients will not be able to create frames in the graphical session.
+      '';
+    };
   };
 
   config = mkIf (cfg.enable || cfg.install) {
@@ -92,7 +101,13 @@ in
         ExecStop = "${cfg.package}/bin/emacsclient --eval (kill-emacs)";
         Restart = "always";
       };
-    } // optionalAttrs cfg.enable { wantedBy = [ "default.target" ]; };
+
+      unitConfig = optionalAttrs cfg.startWithGraphical {
+        After = "graphical-session.target";
+      };
+    } // optionalAttrs cfg.enable {
+      wantedBy = if cfg.startWithGraphical then [ "graphical-session.target" ] else [ "default.target" ];
+    };
 
     environment.systemPackages = [ cfg.package editorScript desktopApplicationFile ];