Rust Nix Bootstrap

Bootstrap Rust projects with a complete Nix flake development environment.

Workflow

1. Detect or Ask Project Type

Check if targeting an existing project (has Cargo.toml). If new project, ask:

•CLI app: Binary with argument parsing
•Library: Reusable crate
•Workspace: Multi-crate project

2. Gather Project Info

•Project name (use directory name if existing, otherwise ask)
•Brief description (for flake.nix and Cargo.toml)

3. Generate Files

Copy and customize templates from assets/:

Template	Output	Notes
`flake.nix.template`	`flake.nix`	Replace `{{PROJECT_NAME}}`, `{{PROJECT_DESCRIPTION}}`
`envrc.template`	`.envrc`	Copy as-is
`justfile.template`	`justfile`	Copy as-is
`ci.yml.template`	`.github/workflows/ci.yml`	Copy as-is

4. Generate Cargo.toml (New Projects Only)

toml

[package]
name = "{{PROJECT_NAME}}"
version = "0.1.0"
edition = "2024"
description = "{{PROJECT_DESCRIPTION}}"

[dependencies]
serde = { version = "1", features = ["derive"] }
tokio = { version = "1", features = ["full"] }
chrono = { version = "0.4", features = ["serde"] }
# Add for CLI only:
clap = { version = "4", features = ["derive"] }

5. Generate src/ (New Projects Only)

CLI app (src/main.rs):

rust

use clap::Parser;

#[derive(Parser, Debug)]
#[command(author, version, about)]
struct Args {
    #[arg(short, long)]
    name: Option<String>,
}

#[tokio::main]
async fn main() {
    let args = Args::parse();
    println!("Hello, {}!", args.name.as_deref().unwrap_or("world"));
}

Library (src/lib.rs):

rust

pub fn add(left: u64, right: u64) -> u64 {
    left + right
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn it_works() {
        assert_eq!(add(2, 2), 4);
    }
}

Workspace (Cargo.toml at root):

toml

[workspace]
resolver = "2"
members = ["crates/*"]

[workspace.dependencies]
serde = { version = "1", features = ["derive"] }
tokio = { version = "1", features = ["full"] }
chrono = { version = "0.4", features = ["serde"] }

Then create crates/{{PROJECT_NAME}}/ with its own Cargo.toml and src/.

6. Initialize Git and Nix

bash

git init  # if not already a repo
echo ".direnv" >> .gitignore
cargo generate-lockfile  # needed for flake

7. Remind User

After generation, remind:

•Run direnv allow to activate the dev shell
•Or nix develop to enter manually
•just to see available commands