How to get path to QT plugins into custom environment variable

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1

Hi, I’m trying to run net-logger so I can run my local ham-radio nets. I’m 90% of the way there but it uses a custom environment variable (NETLOGGER_QT_PLUGINS_PATH) to load qt 5 plugins (which I think is just the location of libqgif.so and libqjpeg.so) and core-dumps if it’s set to an empty string.

I want to use wrapQtArgs to set the variable but first how do I find where the plugins are? is there some build variable like ${qtbase}/plugins that I can use?

the default.nix is

let
  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-26.05";
  pkgs = import nixpkgs { config = {}; overlays = []; };
in
{
  netlogger = pkgs.qt5.callPackage ./netlogger.nix { };
}

and netlogger.nix is

{
  mkDerivation,
  qtbase,
  fetchzip,
  autoPatchelfHook,
  pkgs,
}:

mkDerivation {
  pname = "NetLogger";
  version = "3.1.7";

  buildInputs = [
    pkgs.gnutls
    qtbase
  ];
  # this is a script we will need in the `postFixup` phase witch patches
  # the library paths in the (pre-built) executable
  nativeBuildInputs = [ 
     pkgs.qt5.wrapQtAppsHook   # this provides the dependencies for qt5 apps
     autoPatchelfHook          # but you still need this to rewrite other paths
  ];

  src = fetchzip {
      url = "https://www.netlogger.org/downloads/NetLogger_3.1.7_Linux_x64.tgz";
      stripRoot=false;  # this zip file contains a readme, install script, and a
                        # nested tar file
      hash="sha256-+B1dVx7we+BTuhvFzC38HIS8N2Vb8HdsqLMO4IPgzvQ=";	
  };
  dontBuild = true;
  
  installPhase = ''
	tar -xz -f $src/netlogger_$version.tgz ./netlogger
	chmod u+x ./netlogger
	mkdir -p $out
	mv ./netlogger $out
  '';
}