python
Crash on older versions of Python for a slice in a type subscript
Crash Report
Validating of my python module causes "INTERNAL ERROR"
Traceback
version: 1.11.1
Traceback (most recent call last):
File "/home/sizov/Documents/root/venv/bin/mypy", line 8, in
To Reproduce
write stand-alone example to disk as python file:
from typing import Dict, Optional, Union, List
def copy_attrs(src: Dict[str, Union[str, List[str]]], attr_filter: Optional[List[:str]] = None):
# копируем только str/int и списки str/int
def check_add_attr(dest, key, val):
if isinstance(val, list):
if not val:
raise Exception("Empty index")
val_res = list()
for sub_val in val:
if isinstance(sub_val, str):
sub_val = sub_val.lower()
elif not isinstance(sub_val, int):
return
val_res.append(sub_val)
dest[key] = val_res
return
elif isinstance(val, str):
val = val.lower()
elif not isinstance(val, int):
return
dest[key] = val
dest = dict()
for key, val in list(src.items()):
if attr_filter and key not in attr_filter:
continue
check_add_attr(dest, key, val)
del src[key]
return dest
and call "mypy <stand-alone example>"
My Environment
- Mypy version used: 1.11.1
- Mypy command-line flags: --show-traceback
- Python version used: 3.10.12, 3.8.19
- Operating system and version: Ubuntu 22.04.4 LTS
I'm struggling to reproduce this on mypy-playground or locally. Do you have any configuration files lying around, e.g. pyproject.toml or mypy.ini?
I can reproduce it with Python 3.8.10, but not with a more recent version, like Python 3.11.0.
Thanks, I can reproduce this too on 3.8:
% .venv/bin/python3.8 -m mypy -c 'from typing import List; x: List[:str]' --show-traceback
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: 1.11.1
Traceback (most recent call last):
File "/Users/jelle/Library/Application Support/uv/python/cpython-3.8.19-macos-aarch64-none/lib/python3.8/runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/Users/jelle/Library/Application Support/uv/python/cpython-3.8.19-macos-aarch64-none/lib/python3.8/runpy.py", line 87, in _run_code
exec(code, run_globals)
File "/Users/jelle/py/tmp/.venv/lib/python3.8/site-packages/mypy/__main__.py", line 37, in <module>
console_entry()
File "mypy/build.py", line 2069, in wrap_context
File "mypy/build.py", line 2176, in parse_file
File "mypy/build.py", line 841, in parse_file
File "mypy/parse.py", line 27, in parse
File "mypy/fastparse.py", line 234, in parse
File "mypy/fastparse.py", line 401, in visit
File "mypy/fastparse.py", line 860, in visit_Module
File "mypy/fastparse.py", line 475, in translate_stmt_list
File "mypy/fastparse.py", line 401, in visit
File "mypy/fastparse.py", line 1241, in visit_AnnAssign
File "mypy/fastparse.py", line 1877, in visit
File "mypy/fastparse.py", line 2065, in visit_Subscript
AttributeError: 'NoneType' object has no attribute 'col_offset'
: note: use --pdb to drop into pdb
@VictorSizov the bug in your code is that you have List[:str] instead of List[str]. Fixing that should make the crash go away.
However, of course this is still a bug in mypy; mypy should report an error here instead of crashing.
mypy has dropped support for running with Python 3.8 and this isn't an issue when running mypy with Python 3.9 or newer
