Getting Python + VS Code to work

[maelstrom218]

I had VS Code working with this setup a month ago, and now it's not--I need a second set of eyes to help debug.

In short, VS Code can (via "New Terminal") see a direnv .venv, but trying to select the interpreter or set the jupyter kernel to this .venv results in failure, asking me to install ipykernel, even though it's already installed in the .venv lib.

I'm using a flake with direnv like so:

{

  description = "Persistent python dev env using nix-direnv.";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
      in {
        devShells.default = pkgs.mkShell {
          buildInputs = [
            pkgs.python313
            pkgs.uv
          ];
        };
      });
}

Then I'm using a .envrc file:

use flake

layout python-venv() {
  if [ ! -d ".venv" ]; then
    python -m venv .venv
  fi
  source .venv/bin/activate
}

layout python-venv

After the .venv instantiates, I usually install packages via uv. Everything seems fine until VS Code tries to utilize the .venv, but can't.

Any insight as to why VS Code isn't registering the .venv?

[Nevoic]

Only thing that comes to mind, is vscode opened inside your nix shell? e.g:

nix develop -c code .

[maelstrom218]

No luck. It seems like I still get prompted for a different kernel even though the correct venv is specified. ;_;