TLDR

To start a Rust / Python / Typst project type

nix flake new -t github:jacg/nix-starters#rust ./target-directory

replacing

• rust with python or typst, if appropriate

• ./target-directory with the name of the (not yet existing) directory in which you want the project to be created.

Use Nix to provide isolated, per-project, declarative definitions of dependencies for projects in various languages

• Key assumptions:

  1. The target machine has Nix installed and available to your user.

  2. Nix has the experimental features nix-command and flakes enabled.

     For a legacy version which works with older Nix, see the legacy branch. (TODO: not yet ready)

• Helpful but not strictly necessary: direnv is installed and enabled in your shell.

Quickly bootstrap projects with development environments and dependencies in various languages

1. Create a directory for the project

2. cd into that directory

3. Create the project from a flake template:

   • nix flake init -t github:jacg/nix-starters#rust for a Rust project.
   • nix flake init -t github:jacg/nix-starters#python for a Python project.
   • nix flake init -t github:jacg/nix-starters#typst for Typst.
   • C++ [TODO If you need this, just ask. I do have a solution for a cmake-based project, but cleaning it up and publishing it isn't among my top priorities.

Alternatively, rather than creating the project directory by hand, it can be created by nix flake:

nix flake new -t github:jacg/nix-starters#rust ./project-directory

With direnv

If you have direnv installed and enabled, you should now see the following error message:

direnv: error <your project dierctory>.envrc is blocked. Run `direnv allow` to approve its content

If you trust that the template won't do anything anything malicious on your machine, approve it as suggested by the message: direnv allow.

Check that everything as expected by typing just: you should see some successful test executions.

Henceforth the environment will be activated automatically each time you cd into <your project dir> or any of its subdirectories, and deactivated when you cd back out.

You can withdraw permission for direnv to activate this environment automatically with direnv deny.

If you are using home-manager to provide direnv, you will need

  programs.direnv = {
    enable = true;
    nix-direnv.enable = true;
    nix-direnv.enableFlakes = true;
  };

Without direnv

You can activate the environment manually with nix develop. This will start a new shell with the environment activated. Check that everything as expected by typing just: you should see some successful test executions. Exit the shell, to disable the environment.

Specifying dependencies

The details will vary to some extent from language to language. Broadly speaking, add dependencies to buildInputs in devShell set inside flake.nix.

Take your toolset with you: home-manager

home-manager allows you to reproduce your arbitrarily complex personal toolset and configuration on a new machine, with minimal effort.

BEWARE the git config has contains my name and email address! So make sure to edit home-manager/gitconfig before deploying.

See home-manager/README.md for details. TODO: README does not exist yet.

Pinning

The versions of all the tools and dependencies are pinned: their exact versions are specified in flake.lock. Upgrading can be done with something like:

nix flake lock --update-input nixpkgs