Skip this too without IPV6
MODIFY
dummyserver/testcase.py
dummyserver/testcase.py
@@ -183,6 +183,7 @@ class IPv6HTTPDummyServerTestCase(HTTPDummyServerTestCase):
host = '::1'
+@pytest.mark.skipif(not HAS_IPV6, reason='IPv6 not available')
class IPv6HTTPDummyProxyTestCase(HTTPDummyProxyTestCase):
http_host = 'localhost'

Skip this too without IPV6