Register `tipc` in the tpt tables + test harness

Wire the backend through every registration site (contract §2)
so `--tpt-proto tipc` is a first-class suite mode,
- `_state.TransportProtocolKey` gains the key
- `_addr._address_types` + `._default_lo_addrs`
- `_addr.wrap_address()` gets a `case ('tipc', *_)`; being a
  4-elem seq it can't collide w/ `tcp`s or `uds`s 2-tuple
  cases, so NO ordering hazard (and a bare seq-pattern matches
  the `list` form `msgpack` decodes to).
- `_types`: the `Address` union, `_msg_transports`,
  `_key_to_transport`, `_addr_to_transport` and the
  `transport_from_stream()` family match. That last one keys
  off `._tipc.AF_TIPC` (which carries the uapi fallback) NOT
  `socket.AF_TIPC` which is linux-only.

Test-harness side,
- `get_rando_addr()` gains a `tipc` branch; `.get_random()`
  already salts w/ `uuid4`+pid so both within- and cross-proc
  isolation come for free.
- the `tpt_protos` fixture calls an addr-type's optional
  `.is_available()` and `pytest.fail()`s w/ its reason. Keeps
  a module-less box from turning `--tpt-proto tipc` into a few
  hundred confusing connect-timeouts. Generic on purpose —
  plans 02/03 need the same hook.
- the discovery `daemon` fixture's readiness probe learns to
  dial a TIPC service name (it previously assumed tcp-or-uds
  and blew up on the 4-tuple).

(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))

tractor/_testing/addr.py

@@ -99,6 +99,20 @@ def get_rando_addr(
             assert addr.sockpath.resolve()
             testrun_reg_addr = addr.unwrap()
 
+        # NOTE, `.get_random()` already derives the service
+        # *instance* from a `uuid4`+pid-salted seed, so both the
+        # within- and cross-proc isolation the other 2 protos
+        # hand-roll above comes for free.
+        #
+        # XXX matters MORE here than for tcp/uds: a TIPC name
+        # clash doesn't raise `EADDRINUSE`, it silently
+        # round-robins connects between both publishers.
+        case 'tipc':
+            from tractor.ipc._tipc import TIPCAddress
+            addr: TIPCAddress = addr_type.get_random()
+            assert addr.is_valid
+            testrun_reg_addr = addr.unwrap()
+
     # XXX, as sanity it should never the same as the default for the
     # host-singleton registry actor.
     assert def_reg_addr != testrun_reg_addr

tractor/_testing/pytest.py

@@ -498,14 +498,14 @@ def pytest_configure(
     )
     config.addinivalue_line(
         'markers',
-        'tipc: test targets the `AF_TIPC` tpt backend; the kernel- '
-        'touching cases self-skip unless the `tipc` module is loaded '
-        '(`sudo modprobe tipc`).'
+        'trio: legacy mark for tests meant to run under the `trio` '
+        'spawn backend (e.g. `test_local.py`).'
     )
     config.addinivalue_line(
         'markers',
-        'trio: legacy mark for tests meant to run under the `trio` '
-        'spawn backend (e.g. `test_local.py`).'
+        'tipc: test targets the `AF_TIPC` tpt backend; the kernel- '
+        'touching cases self-skip unless the `tipc` module is loaded '
+        '(`sudo modprobe tipc`).'
     )
 
     # `--enable-stackscope`: install SIGUSR1 → trio task-tree
@@ -803,6 +803,27 @@ def tpt_protos(
         addr_type = _addr._address_types[proto_key]
         assert addr_type.proto_key == proto_key
 
+        # XXX, generic capability gate: an env-dependent tpt
+        # whose backing kernel-mod/lib/netns isn't present here
+        # must fail LOUDLY and EARLY rather than as a few hundred
+        # confusing connect-timeouts downstream.
+        #
+        # Any `Address` type MAY expose `.is_available()`
+        # returning `(ok, why_not)`; absence means "always
+        # available" (i.e. tcp/uds).
+        is_avail = getattr(
+            addr_type,
+            'is_available',
+            None,
+        )
+        if is_avail:
+            avail, why_not = is_avail()
+            if not avail:
+                pytest.fail(
+                    f'--tpt-proto={proto_key!r} is NOT usable here!\n'
+                    f'{why_not}\n'
+                )
+
     yield proto_keys
 
 

tractor/discovery/_addr.py

@@ -36,6 +36,7 @@ from ..ipc._uds import (
     UDSAddress,
     HAS_UDS,
 )
+from ..ipc._tipc import TIPCAddress
 
 if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs ~4.5ms
@@ -200,12 +201,14 @@ class Address(Protocol):
         ...
 
 
-# the address types available on this host: TCP always, UDS only
-# where usable (`HAS_UDS`). Both registries derive from this single
-# list via each type's `proto_key`.
+# the address types supported by this build: TCP and TIPC are
+# importable everywhere, while UDS is registered only where usable
+# (`HAS_UDS`). Runtime TIPC availability is checked separately.
+# Both registries derive from this list via each type's `proto_key`.
 _address_protos: list[Type[Address]] = [TCPAddress]
 if HAS_UDS:
     _address_protos.append(UDSAddress)
+_address_protos.append(TIPCAddress)
 
 _address_types: dict[str, Type[Address]] = {
     cls.proto_key: cls
@@ -270,6 +273,16 @@ def wrap_address(
     #     import pdbp; pdbp.set_trace()
     match addr:
 
+        # XXX, the explicitly proto-keyed form (spelled with the
+        # `multiaddr` proto name) which is where ALL backends
+        # should eventually land per the `UnwrappedAddress`
+        # migration note above.
+        #
+        # NOTE, a bare seq-pattern matches `list` too, which is
+        # what `msgpack` decodes our tuples back to.
+        case ('tipc', *_):
+            cls = TIPCAddress
+
         # classic network socket-address as tuple/list
         case (
             (str(), int())

tractor/ipc/_types.py

@@ -35,20 +35,25 @@ from tractor.ipc._uds import (
     MsgpackUDSStream,
     HAS_UDS,
 )
+from tractor.ipc._tipc import (
+    AF_TIPC,
+    TIPCAddress,
+    MsgpackTIPCStream,
+)
 
-# the UDS backend is importable everywhere but only *usable* when
-# `HAS_UDS` is `True`; otherwise the runtime registers TCP only.
-Address = TCPAddress|UDSAddress
+Address = TCPAddress|UDSAddress|TIPCAddress
 
-# the available msg-transport backends on this host: TCP always,
-# UDS only where usable (`HAS_UDS`). The lookup maps below derive
-# from this single list via each backend's `codec_key` and
-# `address_type`: register a backend here and every map picks it up.
+# the msg-transport backends supported by this build: TCP and TIPC
+# are importable everywhere, while UDS is registered only where
+# usable (`HAS_UDS`). Runtime TIPC availability is checked separately.
+# The lookup maps derive from this list via each backend's `codec_key`
+# and `address_type`.
 _msg_transports: list[Type[MsgTransport]] = [
     MsgpackTCPStream,
 ]
 if HAS_UDS:
     _msg_transports.append(MsgpackUDSStream)
+_msg_transports.append(MsgpackTIPCStream)
 
 # map a `MsgTransportKey` -> `MsgTransport` type
 _key_to_transport: dict[MsgTransportKey, Type[MsgTransport]] = {
@@ -109,6 +114,12 @@ def transport_from_stream(
             ):
                 transport = 'uds'
 
+            # NOTE, `AF_TIPC` is linux-only in CPython so we
+            # match the `._tipc` constant (which carries a uapi
+            # fallback) rather than `socket.AF_TIPC`.
+            case fam if fam == AF_TIPC:
+                transport = 'tipc'
+
             case fam:
                 raise NotImplementedError(
                     f'Unsupported socket family: {fam}'

tractor/runtime/_state.py

@@ -52,6 +52,7 @@ _DARWIN_TMPDIR: Path = Path('/tmp')
 TransportProtocolKey = Literal[
     'tcp',
     'uds',
+    'tipc',
 ]
 _def_tpt_proto: TransportProtocolKey = 'tcp'