python37Packages.httplib: disable tests on darwin

Most of the tests were failing on Mac OS, and tests were only recently
enabled for this package.

pkgs/development/python-modules/httplib2/default.nix

@@ -1,4 +1,5 @@
-{ lib
+{ stdenv
+, lib
 , buildPythonPackage
 , fetchFromGitHub
 , isPy27
@@ -39,8 +40,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
-  # Don't run tests for Python 2.7
+  # Don't run tests for Python 2.7 or Darwin
-  doCheck = !isPy27;
+  # Nearly 50% of the test suite requires local network access
+  # which isn't allowed on sandboxed Darwin builds
+  doCheck = !(isPy27 || stdenv.isDarwin);
   pytestFlagsArray = [ "--ignore python2" ];
   pythonImportsCheck = [ "httplib2" ];