Race.NoRace KeyError from running ./example/watch_replay.py

[JonathanNiehenke]

Running the example/watch_replay.py -- Causes KeyError: <Race.NoRace: 0> from .\sc2\bot_ai_internal.py line 754

python .\watch_replay.py

2025-09-23 19:53:09.714 | INFO | sc2.protocol:_execute:75 - Client status changed to Status.in_replay (was None)
2025-09-23 19:53:09.775 | INFO | sc2.protocol:_execute:75 - Client status changed to Status.in_replay (was None)
2025-09-23 19:53:10.023 | INFO | sc2.sc2process:_close_connection:245 - Closing connection at 56194...
2025-09-23 19:53:10.024 | INFO | sc2.sc2process:kill_all:39 - kill_switch: Process cleanup for 1 processes
Traceback (most recent call last):
File "H:\Source\Language\Python\GWiggins\python-sc2\examples\watch_replay.py", line 43, in
run_replay(my_observer_ai, replay_path=str(replay_path))
File "D:\Python39\lib\site-packages\sc2\main.py", line 498, in run_replay
result = asyncio.get_event_loop().run_until_complete(
File "D:\Python39\lib\asyncio\base_events.py", line 642, in run_until_complete
return future.result()
File "D:\Python39\lib\site-packages\sc2\main.py", line 448, in _host_replay
result = await _play_replay(client, ai, realtime)
File "D:\Python39\lib\site-packages\sc2\main.py", line 247, in _play_replay
ai._prepare_step(gs, proto_game_info)
File "D:\Python39\lib\site-packages\sc2\bot_ai_internal.py", line 667, in _prepare_step
self._prepare_units()
File "D:\Python39\lib\site-packages\sc2\bot_ai_internal.py", line 754, in _prepare_units
if unit_id in race_townhalls[self.race]:
KeyError: <Race.NoRace: 0>

[JonathanNiehenke]

A solution is to add:
Race.NoRace: {},
to race_townhalls within ./sc2/data.py

[JonathanNiehenke]

The error originates in commit: 3ae99a9
That changed observer self.race from Race.Random to Race.NoRace within ./sc2/bot_ai_internal.py

[BurnySc2]

In what scenarios is the race set to Race.NoRace?
Are you trying to watch a replay played on an arcade map?

[JonathanNiehenke]

It happens at the beginning of a regular 1v1 replay. In that instance the replay was created using the worker_rush.py example.
The code making the assignment is within ./sc2/bot_ai_internal.py line 630:

# Get the player's race. As observer, get Race.NoRace=0
self.race: Race = Race(self.game_info.player_races.get(self.player_id, 0))

As long as the self.playerId is not in self.game_info.player_races it defaults to Race.NoRace, which is reasonable as an observer is neither a player nor should it have a race.