devshells

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

  outputs = { self, flake-utils, nixpkgs }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        inherit (nixpkgs) lib;
        pkgs = nixpkgs.legacyPackages.${system};
        rpath = lib.makeLibraryPath (with pkgs; [
          # openssl
          # libressl
        ]);
      in
      {
        devShells.default = pkgs.mkShell {

          nativeBuildInputs = with pkgs; [
            # rustc
            # cargo
            # pkg-config
          ];

          # buildInputs = with pkgs; [
          #   openssl
          #   # libressl
          # ];

          # defines the environment variables
          OPENSSL_DIR= lib.makeLibraryPath (with pkgs; [  
            # openssl 
            ]);
        
          # shellHook = ''
          #   export OPENSSL_DIR=${pkgs.openssl}
          #   '';

          # links the library path dynamically to the shell
          LD_LIBRARY_PATH = rpath;
        };
      }
    );
}

Documentations

mkShell official Docs

https://nixos.org/manual/nixpkgs/stable/#sec-pkgs-mkShell

Flake Parts with all flake realted docs

https://flake.parts

Good Old Wiki

https://nixos.wiki/wiki/Flakes

Python

- python-flake.nix

Implements python flake with automatic .venv implementation with pip install and stuff (flake is self explanatory)

Devenv Implementation

https://devenv.sh/supported-languages/python/#languagespythonversion

languages.python.enable

languages.python.poetry.enable

+ .package siblings

languages.python.libraries (probably not that thing)

Additional libraries to make available to the Python interpreter.

This is useful when you want to use Python wheels that depend on native libraries.

Type: list of path

Default: [ "${config.devenv.dotfile}/profile" ]

Declared by: - https://github.com/cachix/devenv/blob/main/src/modules/languages/python.nix

languages.python.venv.enable

Whether to enable Python virtual environment.

Type: boolean

Default: false

Example: true

Declared by: - https://github.com/cachix/devenv/blob/main/src/modules/languages/python.nix

languages.python.venv.quiet

Whether pip install should avoid outputting messages during devenv initialisation.

Type: boolean

Default: false

Declared by: - https://github.com/cachix/devenv/blob/main/src/modules/languages/python.nix

languages.python.venv.requirements

Contents of pip requirements.txt file. This is passed to pip install -r during devenv shell initialisation.

Type: null or strings concatenated with “\n” or path

Default: null

Declared by: - https://github.com/cachix/devenv/blob/main/src/modules/languages/python.nix

languages.python.version

The Python version to use. This automatically sets the languages.python.package using nixpkgs-python.

Type: null or string

Default: null

Example: "3.11 or 3.11.2"

Declared by: - https://github.com/cachix/devenv/blob/main/src/modules/languages/python.nix