TypeError: _run_asgi2() takes 2 positional arguments but 4 were given (New Relic + Sentry ASGI middleware)

TL;DR

For "TypeError: runasgi2() takes 2 positional arguments but 4 were given": maintainers shipped a fix in the Python agent, so upgrade to 8.5.0 or later. New Relic's wrapt-based instrumentation made Sentry's ASGI middleware mis-detect the app as ASGI v2 instead of v3, so Sentry called the 2-arg v2 handler with 4 args.

TypeError: _run_asgi2() takes 2 positional arguments but 4 were given

Steps

1. New Relic's wrapt-based instrumentation made Sentry's ASGI middleware mis-detect the app as ASGI v2 instead of v3, so Sentry called the 2-arg v2 handler with 4 args. Maintainers shipped a fix in the Python agent, so upgrade to 8.5.0 or later. Note that sentry-python 1.8.0 also improved ASGI auto-detection, so upgrading both is safest. Workaround if you cannot upgrade: force the v3 path with SentryAsgiMiddleware.runasgi2 = SentryAsgiMiddleware.runasgi3 before adding the middleware.

When to use

You are seeing this: Starlette/FastAPI app using SentryAsgiMiddleware plus New Relic's Python agent fails to launch: TypeError: \run\asgi2() takes 2 positional arguments but 4 were given in newrelic/api/asgiapplication.py. Use this skill when you run into "TypeError: run_asgi2() takes 2 positional arguments but 4 were given (New Relic + Sentry ASGI middleware)".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: 8.5.0, sentry-python 1.8.0. If you are on something much newer or older, the details may have shifted.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Edge cases

• Note that sentry-python 1.8.0 also improved ASGI auto-detection, so upgrading both is safest.

Sources

• https://github.com/newrelic/newrelic-python-agent/issues/117

Someone asked: Starlette/FastAPI app using SentryAsgiMiddleware plus New Relic's Python agent fails to launch: TypeError: _run_asgi2() takes 2 positional arguments but 4 were given in newrelic/api/asgiapplication.py. App works fine without newrelic-admin. Triggered by Sentry middleware combined with any other middleware. The verified resolution: New Relic's wrapt-based instrumentation made Sentry's ASGI middleware mis-detect the app as ASGI v2 instead of v3, so Sentry called the 2-arg v2 handler with 4 args. Maintainers shipped a fix in the Python agent, so upgrade to 8.5.0 or later. Note that sentry-python 1.8.0 also improved ASGI auto-detection, so upgrading both is safest. Workaround if you cannot upgrade: force the v3 path with SentryAsgiMiddleware.runasgi2 = SentryAsgiMiddleware.runasgi3 before adding the middleware. Thread: https://vectle.com/threads/thrSD2DUNypGpgK_9HkRMfnKg