How to actually use a packages optional features?

davidak · October 4, 2021, 12:18am

I want to use the program inxi from nix-shell, but it’s broken by default.

[davidak@gaming:~]$ nix run nixpkgs.inxi -c inxi -G
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] driver: amdgpu 
           v: kernel 
           Display: x11 server: X.org 1.20.13 driver: loaded: amdgpu note: n/a (using device driver) 
           resolution: <missing: xdpyinfo> 
           Message: Unable to show advanced data. Required tool glxinfo missing.

There are errors from missing dependencies, but they are actually in the package definition. It’s just not accessible.

github.com

NixOS/nixpkgs/blob/3b6c3bee9174dfe56fd0e586449457467abe7116/pkgs/tools/system/inxi/default.nix#L19


      
          
          
let
            prefixPath = programs:
              "--prefix PATH ':' '${lib.makeBinPath programs}'";
            recommendedSystemPrograms = lib.optionals withRecommendedSystemPrograms [
              util-linuxMinimal dmidecode file hddtemp iproute2 ipmitool usbutils kmod
              lm_sensors smartmontools binutils tree upower pciutils
            ];
            recommendedDisplayInformationPrograms = lib.optionals
              withRecommendedDisplayInformationPrograms
              ([ glxinfo ] ++ (with xorg; [ xdpyinfo xprop xrandr ]));
            programs = [ ps dnsutils ] # Core programs
              ++ recommendedSystemPrograms
              ++ recommendedDisplayInformationPrograms;
          in stdenv.mkDerivation rec {
            pname = "inxi";
            version = "3.3.04-1";
          
          
  src = fetchFromGitHub {
              owner = "smxi";
              repo = "inxi";

So, how to actually use the package?

There seem to be no documentation in search.nixos.org, nixpkgs manual, nix run --help, this forum or nixos.wiki.

I tried this, but it does not do anything:

[davidak@gaming:~]$ nix run nixpkgs.inxi --arg withRecommends true -c inxi -G
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] driver: amdgpu 
           v: kernel 
           Display: x11 server: X.org 1.20.13 driver: loaded: amdgpu note: n/a (using device driver) 
           resolution: <missing: xdpyinfo> 
           Message: Unable to show advanced data. Required tool glxinfo missing.

Does it even make sense that a package is broken by default?

peterhoeg · October 4, 2021, 2:35am

You can override it:

nix-shell -p ‘inxi.override { withRecommends = true; }’ --run ‘inxi -G’

davidak · October 4, 2021, 3:02am

That does work. Thanks!

What about nix run?

peterhoeg · October 4, 2021, 3:22am

What about nix run?

I’m sure there’s a way to do that too with nix run. Doesn’t man nix-run reveal anything?