serial_asyncio_fast is not yet available within debian
To proceed here revert back to serial_asyncio for now.
--- a/src/meshcore/serial_cx.py
+++ b/src/meshcore/serial_cx.py
@@ -4,7 +4,10 @@
 
 import asyncio
 import logging
-import serial_asyncio_fast as serial_asyncio
+try:
+    import serial_asyncio_fast as serial_asyncio
+except ImportError:
+    import serial_asyncio
 
 # Get logger
 logger = logging.getLogger("meshcore")

 
