python3Packages.snitun: disable failing test on darwin

[mweinelt]

Motivation for this change

https://hydra.nixos.org/job/nixpkgs/trunk/python38Packages.snitun.x86_64-darwin

The upstream advertises this package as "OS independent", but from
issues it is clear they cannot test it on MacOS. So we simply disable
this test.

______________________ test_peer_listener_timeout[pyloop] ______________________

raise_timeout = None
peer_manager = <snitun.server.peer_manager.PeerManager object at 0x10a4a6df0>
peer_listener = <snitun.server.listener_peer.PeerListener object at 0x10a4a6a30>
test_client_peer = Client(reader=<StreamReader exception=ConnectionResetError(54, 'Connection reset by peer') transport=<_SelectorSocketT...by peer') transport=<_SelectorSocketTransport closed fd=19>>>, close=<asyncio.locks.Event object at 0x10909ee50 [set]>)

    async def test_peer_listener_timeout(
        raise_timeout, peer_manager, peer_listener, test_client_peer
    ):
        """Run a full flow of with a peer."""
        valid = datetime.utcnow() + timedelta(days=1)
        aes_key = os.urandom(32)
        aes_iv = os.urandom(16)
        hostname = "localhost"
        fernet_token = create_peer_config(valid.timestamp(), hostname, aes_key, aes_iv)

        crypto = CryptoTransport(aes_key, aes_iv)

        test_client_peer.writer.write(fernet_token)
        await test_client_peer.writer.drain()

        with pytest.raises(asyncio.IncompleteReadError):
>           token = await test_client_peer.reader.readexactly(32)

tests/server/test_listener_peer.py:110:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/nix/store/dpa7p7v00xvr26dv2myh3k5p1zkagqsm-python3-3.8.5/lib/python3.8/asyncio/streams.py:723: in readexactly
    await self._wait_for_data('readexactly')
/nix/store/dpa7p7v00xvr26dv2myh3k5p1zkagqsm-python3-3.8.5/lib/python3.8/asyncio/streams.py:517: in _wait_for_data
    await self._waiter
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <_SelectorSocketTransport closed fd=19>

    def _read_ready__data_received(self):
        if self._conn_lost:
            return
        try:
>           data = self._sock.recv(self.max_size)
E           ConnectionResetError: [Errno 54] Connection reset by peer

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[stephank]

Hmm, tests appear to be trouble in general. For example, nixpkgs-review does concurrent builds on Python 3.8 and 3.9 locally, but it's trying to listen on a specific port and bind fails with a conflict. Even with sandboxing, there's no network namespacing, unlike Linux. I don't know how Hydra works, but maybe it schedules builds differently and won't have this issue?

I did separate builds for python38Packages.snitun and python39Packages.snitun, as well as for hass-nabucasa (which nixpkgs-review marked for rebuild) and those builds went fine, but they also work on master. So maybe it was just the port conflict all along? 😕

Now that I have cache locally for those, nixpkgs-review pr 118965 (the certbot PR) also succeeds.

[SuperSandro2000]

@ofborg eval