Mac OS builds fail due to test_site in VSTS for 3.7 branches only

Ref : https://python.visualstudio.com/cpython/_build/results?buildId=17921&view=logs

2018-07-21T07:01:08.5912930Z Traceback (most recent call last):
2018-07-21T07:01:08.5927520Z   File "/Users/vsts/agent/2.136.1/work/1/s/Lib/test/test_site.py", line 199, in test_s_option
2018-07-21T07:01:08.5942120Z     self.assertIn(usersite, sys.path)
2018-07-21T07:01:08.5959870Z AssertionError: '/Users/vsts/.local/lib/python3.7/site-packages' not found in ['/Users/vsts/agent/2.136.1/work/1/s', '/usr/local/lib/python37.zip', '/Users/vsts/agent/2.136.1/work/1/s/Lib', '/Users/vsts/agent/2.136.1/work/1/s/build/lib.macosx-10.13-x86_64-3.7-pydebug', '/usr/local/lib/python3.7/site-packages']
2018-07-21T07:01:08.5971110Z 
2018-07-21T07:01:08.5985860Z ======================================================================
2018-07-21T07:01:08.6000880Z FAIL: test_startup_imports (test.test_site.StartupImportTests)
2018-07-21T07:01:08.6017050Z ----------------------------------------------------------------------
2018-07-21T07:01:08.6033630Z Traceback (most recent call last):
2018-07-21T07:01:08.6048270Z   File "/Users/vsts/agent/2.136.1/work/1/s/Lib/test/test_site.py", line 487, in test_startup_imports
2018-07-21T07:01:08.6063180Z     self.assertFalse(modules.intersection(collection_mods), stderr)
2018-07-21T07:01:08.6079990Z AssertionError: {'reprlib', 'heapq', 'collections', 'keyword', 'operator', 'functools', 'types'} is not false : import _frozen_importlib # frozen

I couldn't find any related issues in search and hence opened this. Feel free to close this if it's a duplicate or fixed in some other branch.

Thanks