[New-bugs-announce] [issue46047] When using Py_NewInterpreter, some modules fail to import in Python 3.10

[Jonas Witschel]

New submission from Jonas Witschel <git at diabonas.de>:

Consider the following minimal example C code which is trying to import jsonschema (https://python-jsonschema.readthedocs.io/en/stable/), compiled using "gcc test_newinterpreter.c -I /usr/include/python3.10 -lpython3.10 -o test_newinterpreter" or similar:

#include <Python.h>

int main(void) {
	Py_Initialize();
	PyThreadState *interpreter = Py_NewInterpreter();
	PyRun_SimpleString("import jsonschema");
	Py_Finalize();	
}

In Python 3.9.9, this works as expected. However in Python 3.10.0, the following error is produced:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python3.10/site-packages/jsonschema/__init__.py", line 21, in <module>
    from jsonschema._types import TypeChecker
  File "/usr/lib/python3.10/site-packages/jsonschema/_types.py", line 168, in <module>
    draft3_type_checker = TypeChecker(
TypeError: TypeChecker() takes no arguments

Removing the Py_NewInterpreter() call makes the example work as expected in Python 3.10.0.

This might be related to the enhancements to the type cache from bpo-42745.

Another recent bug report I found that might possibly be related is bpo-46036.

This bug breaks some WeeChat plugins that try to import one of the affected modules, e.g. weechat-matrix (https://github.com/poljar/weechat-matrix).

----------
components: C API, Subinterpreters
messages: 408295
nosy: diabonas
priority: normal
severity: normal
status: open
title: When using Py_NewInterpreter, some modules fail to import in Python 3.10
type: compile error
versions: Python 3.10

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue46047>
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