lavneetpuri/repylat

Python's latest version template for replit

Template for replit. Fork it here 🥑

Steps to upgrade python to latest version on replit

• Find the desired version in NixOS packages.
• Cross-reference the channel name.
• Create a python repl based on any template. Default one for instance.
• Delete venv folder.
• Copy setup folder to base of the template.
• In .replit file:
  • update channel under [nix] to one that hosts your python package. Note the difference in format (use of _ instead of .)
  • update PYTHONPATH based on new version's expected site-package location.
  • add compile = ["sh", "setup/init.sh"] at the top.
  • update run = ["sh", "setup/main.sh"]
• In replit.nix file:
  • update deps and PYTHONBIN with the nix python pkg you love!
• Run python -m venv venv/ to bootstrap virtual environment. It will contain pip and other necessary packages.
  Since virtual env is already added to path in .replit file, no need to activate.

Info on python LD_LIBRARY_PATH requirement in NixOS:

https://nixos.wiki/wiki/Packaging/Quirks_and_Caveats

PYTHON_LD_LIBRARY_PATH gets set in replit.nix. setup/main.sh wrapper script exists so LD_LIBRARY_PATH doesn't need to be overridden for the whole repl environment. Doing so, crashes programs like nix-channel and many others that rely on default libs.

Most of the supported replit templates solve this by selectively passing env var and entrypoint file to interpreter in .replit file like so:

[interpreter]
  [interpreter.command]
  args = [
    "stderred",
    "--",
    "prybar-python3",
    "-q",
    "--ps1",
    "\u0001\u001b[33m\u0002\u0001\u001b[00m\u0002 ",
    "-i",
  ]
  env = { LD_LIBRARY_PATH = "$PYTHON_LD_LIBRARY_PATH" }

stderred is just to colorize stderr;
prybar-python3 handles termination signals (run/stop button) gracefully;

Here stderred, which comes pre-installed in replit's default nix environment, works fine when *gcc-10.3.0-lib/lib (path of pkgs.stdenv.cc.cc.lib on stable-21_11 nix channel) is present in LD_LIBRARY_PATH. Sadly, upgrade to python v3.10.4 @stable-22_05 also updates pkgs.stdenv.cc.cc.lib to gcc-11.3.0-lib - rendering it incompatible with programs in replit's default nix environment.

Even if we get rid of stderred, prybar-python3 has only been compiled for python3.8 💁‍♂️
For a more robust approach, instead of using this template, you're welcome to configure replit's default nix environment.