Bug report

The standard library module pkgutil.py performs unsafe imports of discovered packages, which can lead to a SystemExit if triggered by an import.

When pkgutil.walk_packages() attempts to import each package (to scan for subpackages), a call to sys.exit() inside the package will trigger an exit of the interpreter. This is in contrast to pydoc, which was made safe with its own pydoc.safeimport(). Attempting to load the documentation for a module that calls sys.exit() will not exit the interpreter.

pkgutil should be made safe in the same manner.

To Reproduce

Create a directory my_pkg and a file my_pkg/__init__.py containing:

# my_pkg/__init__.py
import sys
try:
    import does_not_exist
except ImportError:
    sys.exit(1)

Create a file in the current directory, repro.py, or simply start a REPL and enter:

# repro.py
import pkgutil
import sys
sys.path.insert(0, '.')

def err_handler(modname):
    print(f"Error scanning {modname!r}")

pkgs = [pkgutil.walk_packages(onerror=err_handler)]

Result

The interpreter will exit as soon as it attempts to examine my_pkg.

Expected result

"Error scanning 'my_pkg'" is printed on the console, and the scan continues.

Background

See the recent discussion regarding package-scanning and sys.exit.

Your environment

• CPython versions tested on:

  Python 3.11.2 (main, Feb 8 2023, 00:00:00) [GCC 12.2.1 20221121 (Red Hat 12.2.1-4)] on linux

• Operating system and architecture: Fedora 37 x86_64