ModuleNotFoundError: No module named 'distutils' (Python 3.12+), during pip install or when importing an old package

Cause: distutils was deprecated by PEP 632 and removed from the standard library in Python 3.12. Code or build scripts that still import distutils (old setup.py files, old releases of numpy, pandas or other packages without wheels for your Python, old versions of tools like node-gyp's bundled gyp or virtualenv) fail on 3.12, 3.13 and later. It often appears right after upgrading Python or a base Docker image. How to check: the traceback shows which file does 'import distutils' or 'from distutils ...'. Check python --version and the version of the package being imported or built. Fix (best first): 1. Upgrade the package that uses distutils to a release that supports your Python. Old pinned versions (for example numpy below 1.26 on Python 3.12) are the usual cause; newer releases ship wheels and don't need distutils. 2. If the import comes from a build step, make sure setuptools is installed and recent (pip install --upgrade setuptools). Setuptools provides a compatible distutils replacement that it activates for builds. 3. For your own code, replace distutils uses: setuptools for builds, shutil.copytree / os.makedirs for file helpers, sysconfig for build paths, and packaging.version.Version instead of distutils.version.LooseVersion/StrictVersion. 4. Don't install a 'distutils' package from PyPI as a workaround; it isn't the standard-library module. If you can't update the dependency yet, run that project on Python 3.11 until you can. 5. On Debian/Ubuntu with the system Python, the python3-distutils package only exists for older releases; prefer a virtual environment with current packages. After: reinstall in a fresh virtual environment and run the tests; pin versions that support your Python in requirements so CI doesn't regress. Sources: https://peps.python.org/pep-0632/ https://docs.python.org/3/whatsnew/3.12.html https://setuptools.pypa.io/en/latest/deprecated/distutils-legacy.html