Don't test peercreds lookup under macOS

cheroot/server.py

@@ -1354,6 +1354,8 @@ def get_peer_creds(self):  # LRU cached on per-instance basis, see __init__
 
         try:
             peer_creds = self.socket.getsockopt(
+                # FIXME: Use LOCAL_CREDS for BSD-like OSs
+                # Ref: https://gist.github.com/LucaFilipozzi/e4f1e118202aff27af6aadebda1b5d91  # noqa
                 socket.SOL_SOCKET, socket.SO_PEERCRED,
                 struct.calcsize(PEERCRED_STRUCT_DEF)
             )

cheroot/test/test_server.py

@@ -15,6 +15,7 @@
 import requests_unixsocket
 
 from .._compat import bton, ntob
+from .._compat import IS_MACOS
 from ..server import IS_UID_GID_RESOLVABLE, Gateway, HTTPServer
 from ..testing import (
     ANY_INTERFACE_IPV4,
@@ -30,6 +31,12 @@
 )
 
 
+non_macos_sock_test = pytest.mark.skipif(
+    IS_MACOS,
+    reason='Peercreds lookup does not work under macOS/BSD currently.',
+)
+
+
 @pytest.fixture
 def unix_sock_file():
     """Check that bound UNIX socket address is stored in server."""
@@ -152,6 +159,7 @@ def peercreds_enabled_server_and_client(http_server, unix_sock_file):
 
 
 @non_windows_sock_test
+@non_macos_sock_test
 def test_peercreds_unix_sock(peercreds_enabled_server_and_client):
     """Check that peercred lookup works when enabled."""
     httpserver, testclient = peercreds_enabled_server_and_client
@@ -178,6 +186,7 @@ def test_peercreds_unix_sock(peercreds_enabled_server_and_client):
            'under the current platform',
 )
 @non_windows_sock_test
+@non_macos_sock_test
 def test_peercreds_unix_sock_with_lookup(peercreds_enabled_server_and_client):
     """Check that peercred resolution works when enabled."""
     httpserver, testclient = peercreds_enabled_server_and_client