anchor.diff: -import ./make-test-python.nix ({ pkgs, ... }: {
  +import ./make-test-python.nix ({ pkgs, ... }: let
  +  localProxyPort = 43;
  +in {
     name = "dnscrypt-proxy2";
     meta = with pkgs.lib.maintainers; {
       maintainers = [ joachifm ];
  
positive.code:     # for a caching DNS client.
      client =
      { ... }:
      let localProxyPort = 43; in
      {
        security.apparmor.enable = true;
  
  
negative.code:   testScript = ''
      client.wait_for_unit("dnsmasq")
      client.wait_for_unit("dnscrypt-proxy2")
      client.wait_until_succeeds("ss --numeric --udp --listening | grep -q ${toString localProxyPort}")
    '';
  })
  