Python /opt/python-3.x/ installations missing standard library modules #29

Description

The Python installations in /opt/python-3.x/ on the ubuntu-24.04-riscv runner are missing standard library modules such as math. Attempting to use them as the base interpreter for venv creation fails:

ModuleNotFoundError: No module named 'math'

Additionally, ensurepip is broken even with the system Python (python3.12 from Ubuntu 24.04). After apt-get install python3-venv python3-pip, python3 -m venv /tmp/test still fails with an ensurepip error.

Steps to reproduce

1. On an ubuntu-24.04-riscv runner, run:

   /opt/python-3.12/bin/python3 -m venv /tmp/test

2. Observe: ModuleNotFoundError: No module named 'math'

Or with system Python:

apt-get install -y python3-venv python3-pip
python3 -m venv /tmp/test

Observe: ensurepip error.

Workaround

apt-get install -y python3-venv python3-pip
python3 -m venv --without-pip /tmp/test
curl https://bootstrap.pypa.io/get-pip.py | /tmp/test/bin/python3

Context

Discovered while working on Python wheel builds on the riscv64 runners. Reported as a follow-up to #25.