Add -E command-line flag to bluetoothd

nixos/dustbowl.nix

@@ -3,7 +3,7 @@
 # and in the NixOS manual (accessible by running ‘nixos-help’).
 
 { emacs-overlay, nixpkgs }:
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 
 {
   imports =
@@ -203,24 +203,31 @@
     };
   };
 
+  # Hardware
+
+  # Enable sound.
+  sound.enable = true;
+
+  # Bluetooth
+  hardware.bluetooth.enable = true;
+
+  systemd.services.bluetooth.serviceConfig.ExecStart =
+    let args = [ "-f" "/etc/bluetooth/main.conf" "-E" ];
+    in lib.mkForce [ "" "${config.hardware.bluetooth.package}/libexec/bluetooth/bluetoothd ${lib.escapeShellArgs args}" ];
+
   systemd.user.services.mpris-proxy = {
     description = "Bluetooth mpris-player";
     wantedBy = [ "graphical-session.target" ];
     partOf = [ "graphical-session.target" ];
     serviceConfig = {
       ExecStart = ''
-        ${pkgs.bluez}/bin/mpris-proxy
+        ${config.hardware.bluetooth.package}/bin/mpris-proxy
       '';
       RestartSec = 3;
       Restart = "always";
     };
   };
 
-  # Hardware
-  # Enable sound.
-  sound.enable = true;
-  hardware.bluetooth.enable = true;
-
   # UPower
   services.upower.enable = true;
 
@@ -275,7 +282,7 @@
     backend = "glx";
     vSync = true;
   };
-  systemd.user.services.picom.serviceConfig.Restart = pkgs.lib.mkForce "no";
+  systemd.user.services.picom.serviceConfig.Restart = lib.mkForce "no";
 
   # xss-lock
   programs.xss-lock = {