anchor.diff:      sed -i -e '/alembic>/d' requirements.txt
     '';
   
  -  propagatedBuildInputs = [
  +  propagatedBuildInputs = with python.pkgs; [
       Mako
       aiohttp
       mautrix
  
positive.code:   #
    # Hence we need to patch away `alembic` from `mautrix-telegram` and create an `alembic`
    # which has `mautrix-telegram` in its environment.
    passthru.alembic = alembic.overrideAttrs (old: {
      propagatedBuildInputs = old.propagatedBuildInputs ++ dbDrivers ++ [
        mautrix-telegram
      ];
  
negative.code: { lib, python3, mautrix-telegram, fetchFromGitHub }:
  
  let
    python = python3.override {
      packageOverrides = self: super: {
        sqlalchemy = super.sqlalchemy.overridePythonAttrs (oldAttrs: rec {
          version = "1.3.24";
          src = oldAttrs.src.override {
            inherit version;
            sha256 = "ebbb777cbf9312359b897bf81ba00dae0f5cb69fba2a18265dcc18a6f5ef7519";
          };
        });
      };
    };
  
    # officially supported database drivers
    dbDrivers = with python.pkgs; [
      psycopg2
      # sqlite driver is already shipped with python by default
    ];
  
  in python.pkgs.buildPythonPackage rec {
    pname = "mautrix-telegram";
    version = "0.9.0";
    disabled = python.pythonOlder "3.7";
  
    src = fetchFromGitHub {
      owner = "tulir";
  