KeyboardInterrupt in the middle of fetching STILL creates an error popup and doesn't interrupt

[Verpous]

This is the same issue as #172 . I tried the fix and it doesn't work. I still get the popup.

I also checked out the code and have something to say about this fix:

if sys.platform == "win32":
    import ctypes
    # Suppress critical error dialogs (like CFFI/GPF popups) on Windows
    # SEM_NOGPFAULTERRORBOX = 0x0002
    ctypes.windll.kernel32.SetErrorMode(0x0002)

Importing your library should not change a global state that affects my program too. Since the error originates from curl_cffi, I expect there to be a way to configure curl to not raise popups. But if their library does not support it, at least the fix ought to be to change this global state only temporarily inside the code block where it's needed.

But that only matters if the fix works, which it doesn't :/

[fastfingertips]

This issue is a follow-up to #172. The previous fix had some side effects and didn't fully resolve the problem. We are working on a better approach.

[Verpous]

I'm watching your fixes because I'm a sneaky bastard and I have a heads up. Unraiseablehook is a great catch, I didn't know it exists. But sadly now that I know about it I tried overriding it myself and it changes the error message in the popup, but doesn't eliminate the popup.

Also, this line hides a bug:

    original_hook = getattr(sys, "unraisablehook", None)
    if original_hook:
        sys.unraisablehook = unraisable_hook
        try:

I'm not sure why you use getattr, I'm assuming it's to cover the case of python version <3.8 where unraiseablehook was not supported? But note that unraiseablehook can also exist and be None, and in that case you will want to override it then restore it. What you really want is:

if hasattr(sys, 'unraiseablehook'):
   # ...

EDIT: now I see your pyproject.toml says you require python >= 3.10, so you don't actually need this check at all.

[fastfingertips]

Yeah, that was just one of the many examples I experimented with. I’ve tried several other approaches behind the scenes, but most of them felt too 'dirty' or like bad practice for a library. I’ve decided to postpone this for now to keep the codebase clean. I feel like this is something curl_cffi should be responsible for handling at a lower level anyway :D

Anyway, if you happen to come across a cleaner, non-intrusive solution for this Windows popup issue in the future, please let me know! I'd love to hear your thoughts.

[Verpous]

@fastfingertips You're right, if curl_cffi is responsible for this popup it's their bug not yours.

I tried to build this minimal reproducible example based on your code:

import curl_cffi
import curl_cffi.requests

headers = {
    "referer": "https://letterboxd.com",
    "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7",
    "accept-encoding": "gzip, deflate, br",
    "accept-language": "en-US,en;q=0.9",
    "connection": "keep-alive",
}
    
session = curl_cffi.requests.Session()
response = session.get(
    'https://letterboxd.com',
    headers=headers,
    impersonate='chrome',
)
print(response.text)

What I find is that Ctrl+C in the middle of this actually doesn't reproduce the issue! Instead I get a normal-ish looking exception:

Exception ignored from cffi callback <function buffer_callback at 0x000002551EA6C220>:
Traceback (most recent call last):
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\curl.py", line 125, in buffer_callback
    @ffi.def_extern()

KeyboardInterrupt:
Traceback (most recent call last):
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\requests\session.py", line 732, in _request_once
    c.perform()
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\curl.py", line 505, in perform
    self._check_error(ret, "perform")
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\curl.py", line 269, in _check_error
    raise error
curl_cffi.curl.CurlError: Failed to perform, curl: (23) Failure writing output to destination, passed 13 returned 0. See https://curl.se/libcurl/c/libcurl-errors.html first for more details.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\edery\Desktop\test.py", line 13, in <module>
    response = session.get(
               ^^^^^^^^^^^^
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\requests\session.py", line 842, in get
    return self.request(method="GET", url=url, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\requests\session.py", line 795, in request
    return self._request_once(
           ^^^^^^^^^^^^^^^^^^^
  File "C:\Users\edery\AppData\Local\Programs\Python\Python312\Lib\site-packages\curl_cffi\requests\session.py", line 739, in _request_once
    raise error(str(e), e.code, rsp) from e
curl_cffi.requests.exceptions.RequestException: Failed to perform, curl: (23) Failure writing output to destination, passed 13 returned 0. See https://curl.se/libcurl/c/libcurl-errors.html first for more details.

"Exception ignored from cffi callback <function buffer_callback at 0x000002551EA6C220>:" - I did a little bit more digging, and apparently what's happening is curl_cffi is calling C code which calls this python function and because of that, the exception can't be properly handled, so it's referred to sys.unraisablehook.

Curl does seem to handle these exceptions though somehow. Because if I add an except wrap:

try:
    response = session.get(
        'https://letterboxd.com',
        headers=headers,
        impersonate='chrome',
    )
except curl_cffi.requests.errors.RequestsError as e:
    sys.exit()

It actually catches the interrupt and most of the above traceback is no longer printed (only the first part still is). I can't find where in curl's code they have this handling though.

Anyway, the fact that it doesn't reproduce had me wondering if my python project has a different unraiseablehook than this reproduction, but it doesn't. So now I suspect that maybe letterboxdpy is actually doing something somewhere to which causes curl_cffi to raise this popup. Maybe you're configuring it somehow somewhere, or calling it from a thread, or asyncio, or something like that? It would be interesting to find out where between this minimal example and your actual code the error begins reproducing. Maybe you could move the session.get line around and see.

I've spent too much of my evening investigating this rabbit hole 😓

[fastfingertips]

I've resolved this issue, but I won't prioritize it for now.