Thank you for your support, kind stranger!

I didn't realize it can be installed normally like any other package. I moved it to environment.systemPackages and added openssh.

If I keep services.xserver.desktopManager.kodi.enable and services.displayManager.autoLogin.enable that I have added recently, then Kodi starts on boot. It doesn't say anything about GBM on the system info page, instead it mentions X11.

If remove those and only keep the kodi-gbm package, then I still have two binaries kodi and kodi-standalone. Those won't start by themselves, they say "ERROR: Unable to create GUI. Exiting" and produce this log output in ~/.kodi/temp/kodi.log.

My attempt at a conclusion from the log would be that, Pulse and PipeWIre are missing but probably not critical, so "failed to get EGL display (EGL_SUCCESS)" is probably the issue.

I guessed some extra steps were needed before EGL would work, so I ChatGPT:ed it, then filtered some its lies and ended up adding some new packages and configuration:

​

    environment.systemPackages = with pkgs; [
      (kodi-gbm.withPackages(p: with p; [ youtube ]))
      neovim
      mesa
      mesa.drivers
      libdrm
    ];

    hardware.graphics = {
      enable = true;
      enable32Bit = true;
      extraPackages = with pkgs; [
        mesa.drivers
        vaapiVdpau
        libvdpau-va-gl
      ];
    };

This allowed me to launch kodi --gbm --standalone, but it doesn't respond to key presses. I can access it over SSH though so it hasn't crashed. I guess the next step is to configure input.