The patching code added in #434 breaks if the run attribute on a thread is not a method.

I’m using sentry-sdk==0.11.1 with Python 3.7.4.

Put the following code in demo.py:

import sentry_sdk
from sentry_sdk.integrations.threading import ThreadingIntegration

sentry_sdk.init(default_integrations=False, integrations=[ThreadingIntegration()])

from threading import Thread

class MyThread(Thread):
    def __init__(self):
        super().__init__()
        self.run = lambda: print("hello")

t = MyThread()
t.start()
t.join()

Run python3 demo.py:

Traceback (most recent call last):
  File "demo.py", line 18, in <module>
    t.start()
  File "/myapp/venv/lib/python3.7/site-packages/sentry_sdk/integrations/threading.py", line 41, in sentry_start
    self.run = _wrap_run(hub_, self.run.__func__)
AttributeError: 'function' object has no attribute '__func__'

Remove Sentry:

from threading import Thread

class MyThread(Thread):
    def __init__(self):
        super().__init__()
        self.run = lambda: print("hello")

t = MyThread()
t.start()
t.join()

Run it again: python3 demo.py

hello

It runs fine.

The issue is that the patching code relies on self.run.__func__ but that attribute is only defined on methods, not on functions.

You can see that with this code:

>>> class A():
...     def f(self):
...             pass
...     def set_f(self):
...             self.f = lambda _: 42
...
>>> a = A()
>>> a.f.__func__
<function A.f at 0x106dfaef0>
>>> a.set_f()
>>> a.f.__func__
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'function' object has no attribute '__func__'

According to the Python docs, one can call inspect.ismethod on an object to check if it’s a method and so if it has a ___func__ attribute (you could even use hasattr).

I haven’t tested it, but I believe something like this would do the job:

run_function = self.run.__func__ if inspect.ismethod(self.run) else self.run
self.run = _wrap_run(hub_, run_function)

Note that this self.run assigment code (already in the patch) transforms self.run in a function rather than a method if it were one before, meaning that in my example code MyThread().run.__func__ is defined only if I don’t use Sentry (or at least its Thread integration).

What do you think? I can move forward and make a pull-request with a test and a fix if the solution above suits you.