test_support.test_change_cwd is failing on macOS

[slozier]

The test exercises support.change_cwd which basically does:

def change_cwd(path):
    saved_dir = os.getcwd()
    os.chdir(path)
    try:
        yield os.getcwd()
    finally:
        os.chdir(saved_dir)

and then checks that the directory is what's expected. However this is failing with an assertion error:

AssertionError: '/private/var/folders/some_folder' != '/var/folders/some_folder'