The error is quite clear:
evaluation aborted with the following error message: 'Function called without required argument "buildPythonPackage" at /home/thiloho/dev/nixpkgs/pkgs/by-name/xe/xenon/package.nix:2'
Your nix file contain a function that expects three arguments: lib, buildPythonPackage, fetchFromGitHub and you provided none. The same question (with a a different package) was asked and answered here: Need help on failing build - packaging onedriver for nixos