Environment:

• python 3.8.5

• awslambdarie (v1.0)

• awslambdaric (v1.0.0)

• sentry-sdk==0.19.5

• handler in a submodule, ie run with:

  aws-lambda-rie python -m awslambdaric my_module.app_module

• After fixing: AWS Lambda integration cannot detect awslambdaric bootstrap correctly #972

After handling an exception and sending it to sentry.io, sentry handler crashes with:

    UnboundLocalError: local variable 'timeout_thread' referenced before assignment
    Traceback (most recent call last):
       File "/usr/local/lib/python3.8/dist-packages/sentry_sdk/integrations/aws_lambda.py", line 160, in sentry_handler
        if timeout_thread:

Sentry event does appear on sentry.io, so it was successfully sent before this error. However this error acts as a lambda request failure as far as the ric and rie are concerned.