AttributeError: type object 'Flask' has no attribute 'try_trigger_before_first_request_functions'

[apoclyps]

Which version of dd-trace-py are you using?

ddtrace=1.3.0

Which version of pip are you using?

# pip --version
pip 22.0.4 from /usr/local/lib/python3.10/site-packages/pip (python 3.10)

Which version of the libraries are you using?

Flask = 2.2.0
ddtrace = 1.3.0

How can we reproduce your problem?

Install the following dependencies

pip install Flask==2.2.0
pip install ddtrace==1.3.0

created the following main.py

from ddtrace import patch_all
from flask import Flask

patch_all()

app = Flask(__name__)

@app.route("/")
def hello_world():
    return "<p>Hello, World!</p>"

run the following command:

ddtrace-run flask --app main run

What is the result that you get?

Traceback (most recent call last):
  File "/usr/local/bin/flask", line 5, in <module>
    from flask.cli import main
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/importer.py", line 177, in _exec_module
    notify_module_loaded(module)
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/decorators.py", line 470, in _synchronized
    return wrapped(*args, **kwargs)
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/importer.py", line 136, in notify_module_loaded
    hook(module)
  File "/usr/local/lib/python3.10/site-packages/ddtrace/_monkey.py", line 143, in on_import
    imported_module.patch()
  File "/usr/local/lib/python3.10/site-packages/ddtrace/contrib/flask/patch.py", line 111, in patch
    _w("flask", "Flask.{}".format(name), simple_tracer("flask.{}".format(name)))
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/wrappers.py", line 870, in wrap_function_wrapper
    return wrap_object(module, name, FunctionWrapper, (wrapper,))
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/wrappers.py", line 816, in wrap_object
    (parent, attribute, original) = resolve_path(module, name)
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/wrappers.py", line 808, in resolve_path
    original = lookup_attribute(parent, attribute)
  File "/usr/local/lib/python3.10/site-packages/ddtrace/vendor/wrapt/wrappers.py", line 800, in lookup_attribute
    return getattr(parent, attribute)
AttributeError: type object 'Flask' has no attribute 'try_trigger_before_first_request_functions'

What is the result that you expected?

Service starts successfully without raising an attribute error when datadog is enabled.

Current understanding of the issue

Flask removed try_trigger_before_first_request_functions in pallets/flask#4621 which was released as the 2.2.0 version of Flask.