Rust Nix Flake Template

This template provides a reproducible Rust development environment using Nix flakes and the fenix toolchain.

Quick Start

nix develop
# or with direnv:
direnv allow

Automatic Environment Setup

When you enter the devShell (via direnv allow or nix develop), the following happens automatically:

✓ Git Repository: Initializes .git if not present ✓ Rust Targets: Automatically adds common embedded Rust targets (ARM Cortex-M, RISC-V) ✓ Cargo Paths: Sets up $HOME/.cargo/bin in PATH for cargo-installed binaries ✓ Welcome Banner: Displays available tools and quick commands

No manual setup needed! Just start coding.

Quickstart

nix flake init -t path:../flakes#rust
nix develop
cargo build

Embedded Rust Support

The devShell automatically installs common embedded Rust targets via rustup:

Target	Platform	Use Case
thumbv6m-none-eabi	ARM Cortex-M0/M0+	RP2040 (Pico)
thumbv7em-none-eabihf	ARM Cortex-M4F/M7F	STM32, nRF52840
riscv32imc-unknown-none-elf	RISC-V 32-bit	ESP32-C3 (basic)
riscv32imac-unknown-none-elf	RISC-V 32-bit (atomic)	ESP32-C3 (advanced)

Note: ESP32 Xtensa targets require espup or custom toolchains (see esp-rs).

Flatpak Packaging

This template supports building Flatpak packages for your Rust application.

Build Flatpak Package

1. Ensure you have flatpak-builder installed.
2. Run:

make flatpak-build

This will use the manifest at flatpak/app.flatpak.json to build a Flatpak bundle in the build-flatpak/ directory.

Customize Manifest

Edit flatpak/app.flatpak.json to update app ID, runtime, build commands, or sources as needed for your project.

Install/Run Flatpak Locally

You can install and run the built Flatpak locally:

flatpak install --user build-flatpak/org.example.rustdevshell.flatpak
flatpak run org.example.rustdevshell

Included Tools

Tool	Purpose
cargo	Rust package manager and build system
rustc	Rust compiler
clippy	Rust linter for catching common mistakes
rustfmt	Rust code formatter
rust-analyzer	Language server for IDE integration
rust-src	Rust source code (for tools like rust-analyzer)
probe-rs	Embedded debugger/flasher for ARM targets
espflash	Flashing tool for ESP32 boards
openocd	JTAG/SWD debugger for ARM and other targets
minicom	Serial terminal for device output
elf2uf2-rs	Convert ELF to UF2 format (RP2040)
picotool	Pico-specific firmware operations
avrdude	AVR microcontroller programmer
ravedude	Rapid AVR development utility

Testing & Development Features

Build and testing tools:

• cargo test - Run unit and integration tests
• cargo clippy - Lint code for common issues
• cargo fmt - Format code consistently with rustfmt

Example usage:

# Run tests
cargo test

# Check code with clippy
cargo clippy

# Format code
cargo fmt

# Build for embedded target
cargo build --target thumbv7em-none-eabihf --release

Project Layout

Cargo.toml
Cargo.lock
src/
  └── main.rs (or lib.rs)
Makefile
.envrc
flake.nix

Legacy Usage

If you do not use flakes, run:

nix-shell

Project Metadata

See project.toml for example metadata.

Helper Tools

• nix run .#dev-helper - Display tool versions and availability
• cargo build - Build the project
• cargo check - Quick syntax check without building
• cargo doc --open - Generate and view documentation

Packaging for nixpkgs

This template is structured for easy packaging in nixpkgs:

• All sources in src/
• flake.nix provides a devShell and template
• Add a default.nix or package expression as needed for nixpkgs

See nixpkgs Rust packaging docs for more details.

Customization

Edit flake.nix to:

• Add additional Rust targets via rustup target add [target]
• Include additional cargo plugins
• Add board-specific tools (e.g., stm32cube, nrfjprog)