diff --git a/tests/conftest.py b/tests/conftest.py
index 1fad2255..c7b20531 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -212,7 +212,7 @@ def sig_prog(
     '''
     for i in range(tries):
         proc.send_signal(sig)
-        if not proc.poll():
+        if proc.poll() is None:
             print(
                 f'WARNING, proc still alive after,\n'
                 f'canc_timeout={canc_timeout!r}\n'
@@ -224,8 +224,7 @@ def sig_prog(
     else:
         # TODO: why sometimes does SIGINT not work on teardown?
         # seems to happen only when trace logging enabled?
-        if not proc.poll():
-            breakpoint()
+        if proc.poll() is None:
             print(
                 f'XXX WARNING KILLING PROG WITH SIGINT XXX\n'
                 f'canc_timeout={canc_timeout!r}\n'
diff --git a/tractor/discovery/__init__.py b/tractor/discovery/__init__.py
index 93c19e62..1ac8415d 100644
--- a/tractor/discovery/__init__.py
+++ b/tractor/discovery/__init__.py
@@ -18,10 +18,11 @@
 Discovery (protocols) API for automatic addressing
 and location management of (service) actors.
 
-NOTE: to avoid circular imports, this ``__init__``
-does NOT eagerly import submodules. Use direct
-module paths like ``tractor.discovery._addr`` or
-``tractor.discovery._api`` instead.
+NOTE: this ``__init__`` only eagerly imports the
+``._multiaddr`` submodule (for public re-exports).
+Heavier submodules like ``._addr`` and ``._api``
+are NOT imported here to avoid circular imports;
+use direct module paths for those.
 
 '''
 from ._multiaddr import (
diff --git a/tractor/discovery/_registry.py b/tractor/discovery/_registry.py
index dd235753..7cedb391 100644
--- a/tractor/discovery/_registry.py
+++ b/tractor/discovery/_registry.py
@@ -196,6 +196,8 @@ class Registrar(Actor):
                 and addr_tup in other_addrs
             ):
                 other_addrs.remove(addr_tup)
+                if not other_addrs:
+                    del self._registry[other_uid]
                 break
 
         # Append to this uid's addr list (avoid duplicates)
diff --git a/tractor/runtime/_runtime.py b/tractor/runtime/_runtime.py
index 6ff669a7..bee9e20d 100644
--- a/tractor/runtime/_runtime.py
+++ b/tractor/runtime/_runtime.py
@@ -1567,7 +1567,7 @@ async def async_main(
         # XXX, either passed in by caller or delivered
         # in post spawn-spec handshake for subs.
         if not accept_addrs:
-            RuntimeError(
+            raise RuntimeError(
                 f'No tpt bind addresses provided to actor!?\n'
                 f'parent_addr={parent_addr!r}\n'
                 f'accept_addrs={accept_addrs!r}\n'
@@ -1926,7 +1926,7 @@ async def async_main(
                 if failed_unreg:
                     teardown_report += (
                         f'-> Failed to unregister {actor.name} from '
-                        f'registar @ {addr}\n'
+                        f'registrar @ {addr}\n'
                     )
 
         # Ensure all peers (actors connected to us as clients) are finished