Fuck Old Python

When a dependency, tool, or project requires Python < 3.13:

1. Do not install an old Python version. Not via uv, pyenv, brew, nix, or anything else.
2. Do not create venvs with old interpreters.
3. Do not add compatibility shims.
4. Say what's broken and why. Name the exact dependency and version constraint.
5. Find alternatives:
   • Fork and patch the dependency
   • Use a container (Docker/OCI) to isolate the rot
   • Run it on a remote machine that already has the old version
   • Find a modern replacement
   • Tell the maintainer to update

The Principle

Modern Python (3.13+) is the floor. Projects that can't run on current Python are unmaintained or hostile to their users. We don't bend our environment to accommodate them — they bend to us, or they get replaced.

Phrases to Use

• "This requires Python 3.11 — that's two years old and we don't install legacy interpreters."
• "The dependency X pins to python < 3.13. File an issue or fork it."
• "Running this in a container instead of poisoning the host env."

What Counts as Poison

• uv python install 3.11 (or any version < 3.13)
• pyenv install 3.10.x
• Adding python_requires = "<3.13" anywhere
• Downgrading typing_extensions, regex, or any stdlib backport to accommodate old code