Crash with BeautifulSoup

[cap-jmk]

The bug produces as internal error when accessing the dict returned from BeautifulSoup.find_all() method:
on: 0.991

I would rather expect an mypy error instead on an internal error. 
**To Reproduce**

```python
repos = []
    for url in links:
        soup = BeautifulSoup(urlopen(url), "html.parser")
        for link in soup.find_all("a", href=True):
            repos.append(repos.append(link["href"])

Expected Behavior

I would expect some sort of mypy error.

Actual Behavior

error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
If this issue continues with mypy master, please report a bug at https://github.com/python/mypy/issues

Yet, when using the following

mypy --strict package_name/ --show-traceback

The result is

error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 0.991
Traceback (most recent call last):
  File "mypy/checkexpr.py", line 4657, in accept
  File "mypy/checkexpr.py", line 410, in visit_call_expr
  File "mypy/checkexpr.py", line 473, in visit_call_expr_inner
  File "mypy/checkexpr.py", line 885, in try_infer_partial_type
KeyError: <mypy.nodes.Var object at 0x7f3843b28670>

Thus, I am reporting the bug.

Your Environment

• Mypy version used: 0.991
• Mypy command-line flags: --strict, --show-traceback
• Mypy configuration options from mypy.ini (and other config files): no special config
• Python version used: 3.10

[JelleZijlstra]

Crashes like this are definitely bugs that we should fix. Could you provide a complete, self-contained code sample that reproduces the error?

[cap-jmk]

Yes, of course. Sorry I thought the first would suffice. My bad.

from typing import  List
from bs4 import BeautifulSoup
from urllib.request import urlopen

def get_repos(
    git_links:List[str]=[
        "www.google.com",
        "www.bing.com",
    ],
):

    repos = []
    print(git_links)
    for url in git_links:
        soup = BeautifulSoup(urlopen(url), "html.parser")
        for link in soup.find_all("a", href=True):
            repos.append(repos.append(link["href"]))


if name == "__main__": 
    get_repos()

Then if you run

mypy --strict file_name.py

It gives the error on Python3.10

[uriyyo]

@cap-jmk Main issue here in this line:

repos.append(repos.append(link["href"]))

You are trying to append the result of append call to list.

You just need to change your code to:

from typing import  List
from bs4 import BeautifulSoup
from urllib.request import urlopen

def get_repos(
    git_links:List[str]=[
        "www.google.com",
        "www.bing.com",
    ],
):

    repos = []
    print(git_links)
    for url in git_links:
        soup = BeautifulSoup(urlopen(url), "html.parser")
        for link in soup.find_all("a", href=True):
            repos.append(link["href"])


if __name__ == "__main__":
    get_repos()