Debugging slow/failing call to config flow API

Hey folks,

With some integrations, it’s not possible to set them up because the API call to /api/config/config_entries/flow hangs.

When this happens, nothing shows in the logs, and even when profiling HA, nothing seems to show up to show where the hang is.

I’ve put this into the development category as I’d like to know how to debug it myself and find the root cause rather than just yelling at integration maintainers!

Any ideas as to how to work out what’s going on?