Solutions to common or potentially confusing problems are documented here.
ASGI 'lifespan' protocol appears unsupported
Uvicorn 7.0+ outputs this if an exception occurred during application startup. You can make Uvicorn log the exception by passing
uvicorn myproject.asgi:app --lifespan=on
In particular, this may occur if you use Bocadillo 0.14+ and did not call
configure() before serving the application (see Configuration).