Throw when trying to create a session without the dependency

discord/gateway.py

@@ -992,7 +992,8 @@ class DiscordVoiceWebSocket:
             self._connection.mode = data['mode']
             await self.load_secret_key(data)
             self._connection.dave_protocol_version = data['dave_protocol_version']
-            await self._connection.reinit_dave_session()
+            if data['dave_protocol_version'] > 0:
+                await self._connection.reinit_dave_session()
         elif op == self.HELLO:
             interval = data['heartbeat_interval'] / 1000.0
             self._keep_alive = VoiceKeepAliveHandler(ws=self, interval=min(interval, 5.0))

discord/voice_state.py

@@ -266,7 +266,7 @@ class VoiceConnectionState:
 
     @property
     def max_dave_protocol_version(self) -> int:
-        return davey.DAVE_PROTOCOL_VERSION
+        return davey.DAVE_PROTOCOL_VERSION if has_dave else 0
 
     @property
     def can_encrypt(self) -> bool:
@@ -274,6 +274,8 @@ class VoiceConnectionState:
 
     async def reinit_dave_session(self) -> None:
         if self.dave_protocol_version > 0:
+            if not has_dave:
+                raise RuntimeError('davey library needed in order to use E2EE voice')
             if self.dave_session:
                 self.dave_session.reinit(self.dave_protocol_version, self.user.id, self.voice_client.channel.id)
             else: