dotfiles/devshells

Development Shells

This directory contains modular Nix devShell configurations for various programming languages and use cases.

Available Shells

Note: When in the dotfiles directory, use .#shell-name. From other directories, use the full path ~/Development/dotfiles#shell-name.

default

Basic shell with git and nixfmt for dotfiles development.

nix develop        # or: nix develop .#default

Includes:

• Git
• nixfmt-classic
• uv (for uvx commands)

MCP helper:

• mcp-nixos alias pins UV caches to .cache/ so uvx mcp-nixos works without extra setup; useful before launching Codex.

python-uv

Python development with UV package manager.

nix develop .#python-uv

Includes:

• Python 3.12
• UV (fast Python package manager)
• Ruff (linter/formatter)
• Pyright (type checker)

ml-ai

Machine Learning and AI development with HuggingFace model management.

nix develop .#ml-ai

Includes:

• Python 3.12 with huggingface-hub
• huggingface-cli for downloading models
• UV for package management
• Git LFS for large files
• Ruff and Pyright

Model cache: ~/.cache/huggingface (persistent across projects)

Example usage:

# Download a TTS model
huggingface-cli download facebook/mms-tts-eng

# Download a small LLM
huggingface-cli download meta-llama/Llama-3.2-1B

# Download specific files only
huggingface-cli download openai/whisper-large-v3 --include "*.json" "*.safetensors"

# Use in your project
uv init my-ml-project
cd my-ml-project
uv add transformers torch

go

Go development environment.

nix develop .#go

Includes:

• Go compiler
• gopls (language server)
• golangci-lint
• delve (debugger)

web-bun

Modern web development with Bun runtime.

nix develop .#web-bun

Includes:

• Bun
• Node.js 20
• Yarn
• esbuild
• vscode-langservers-extracted

rust

Rust development environment.

nix develop .#rust

Includes:

• Cargo & rustc
• rust-analyzer
• rustfmt
• clippy

zig-nightly (optional)

Zig nightly development (only available if zig overlay is working).

nix develop .#zig-nightly

Usage from Any Directory

Option 1: Direct Path Reference

Use the full path to your dotfiles:

cd ~/my-project
nix develop ~/Development/dotfiles#ml-ai

Option 2: Flake Registry Alias (Recommended)

One-time setup:

nix registry add dotfiles ~/Development/dotfiles

# Verify it worked
nix registry list | grep dotfiles

Then from anywhere:

cd ~/any-project
nix develop dotfiles#ml-ai

Benefits: Shorter commands, cleaner paths, easy to remember!

Option 3: Auto-loading with direnv (Best for per-project)

Recommended: Combine registry + direnv for cleanest setup:

# One-time: Set up registry (if not done already)
nix registry add dotfiles ~/Development/dotfiles

# In each project:
cd ~/my-ml-project
echo "use flake dotfiles#ml-ai" > .envrc
direnv allow

Alternative: Without registry (using full path):

cd ~/my-ml-project
echo "use flake ~/Development/dotfiles#ml-ai" > .envrc
direnv allow

Now the shell automatically activates when you cd into that directory!

Option 4: Project-specific flake.nix

Create a flake.nix in your project that imports the shell:

{
  inputs = {
    dotfiles.url = "path:/Users/rasyidanakbar/Development/dotfiles";
  };

  outputs = { self, dotfiles }:
    let
      system = "aarch64-darwin";
    in {
      devShells.${system}.default = dotfiles.devShells.${system}.ml-ai;
    };
}

Then simply:

cd ~/my-project
nix develop

Quick Reference

Method	Command	Pros
Direct path	nix develop ~/Development/dotfiles#ml-ai	Simple, no setup
Registry	nix develop dotfiles#ml-ai	Clean, short commands
direnv + registry	echo "use flake dotfiles#ml-ai" > .envrc	Auto-loads, clean
Project flake	nix develop	Shareable, version-controlled

Adding New Shells

1. Create a new file in devshells/ (e.g., devshells/java.nix)
2. Follow the pattern:

{ pkgs, ... }:

pkgs.mkShell {
  name = "java";
  packages = with pkgs; [ jdk maven ];
  shellHook = ''
    echo "Java development shell ready"
  '';
}

3. Add it to flake.nix imports:

java = importShell "java";

4. Test: nix flake check