Flask auto-instrumentation w/ debug=True doesn't work

[codeboten]

Describe your environment
Using the auto-instrumentation example https://opentelemetry-python.readthedocs.io/en/latest/examples/auto-instrumentation/README.html and enabling debug=True in app.run disables instrumentation.

Steps to reproduce
Follow the example and update the code to enable debug mode in flask

What is the expected behavior?
Traces are emitted

What is the actual behavior?
No trace is emitted

[codeboten]

This appears to be a limitation when using the reloader, maybe related to open-telemetry/opentelemetry-python#1794

[github-actions]

This issue was marked stale due to lack of activity. It will be closed in 30 days.

[lzchen]

@ocelotl
Is this resolved?

[ocelotl]

@lzchen, yes closing 👍

[tha2015]

It looks like a limitation of the new version ( See open-telemetry/opentelemetry-python#1800 (comment) ). And although it was documented, I really hope it can be supported.

[NathanielRN]

This was closed in open-telemetry/opentelemetry-python#1795 with an update to the documentation explaining how to get around this issue.

However I agree with @tha2015 that this is really easy to miss, so I mentioned in this new issue #546 (comment) that we should probably come up with another solution to make the issue more obvious.