treewide: disable checks on darwin

Not working in these cases:

- dconf
- paho-mqtt
- perl-gtk2
- perl-TAPParserSourceHandlerpgTAP

pkgs/desktops/gnome-3/core/dconf/default.nix

@@ -38,7 +38,7 @@ stdenv.mkDerivation rec {
     "-Dgtk_doc=true"
   ];
 
-  doCheck = !stdenv.isAarch64;
+  doCheck = !stdenv.isAarch64 && !stdenv.isDarwin;
 
   passthru = {
     updateScript = gnome3.updateScript {

pkgs/development/python-modules/paho-mqtt/default.nix

@@ -1,5 +1,5 @@
 { lib, buildPythonPackage, fetchFromGitHub, isPy3k
-, pytestrunner, pytest, mock }:
+, stdenv, pytestrunner, pytest, mock }:
 
 buildPythonPackage rec {
   pname = "paho-mqtt";
@@ -20,6 +20,8 @@ buildPythonPackage rec {
 
   checkInputs = [ pytestrunner pytest ] ++ lib.optional (!isPy3k) mock;
 
+  doCheck = !stdenv.isDarwin;
+
   meta = with lib; {
     homepage = https://eclipse.org/paho;
     description = "MQTT version 3.1.1 client class";

pkgs/top-level/perl-packages.nix

@@ -6676,6 +6676,7 @@ let
       sha256 = "1044rj3wbfmgaif2jb0k28m2aczli6ai2n5yvn6pr7zjyw16kvd2";
     };
     buildInputs = [ pkgs.gtk2 Cairo ExtUtilsDepends ExtUtilsPkgConfig Glib Pango ];
+    doCheck = !stdenv.isDarwin;
     meta = {
       homepage = http://gtk2-perl.sourceforge.net/;
       description = "Perl interface to the 2.x series of the Gimp Toolkit library";
@@ -14641,6 +14642,7 @@ let
       sha256 = "1msxg3j1hx5wsc7vr81x5gs9gdbn4y0x6cvyj3pq4dgi1603dbvi";
     };
     propagatedBuildInputs = [ AppConfig ];
+    doCheck = !stdenv.isDarwin;
     meta = {
       description = "Comprehensive template processing system";
       license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];