RCargo - Rust Cargo Wrapper with Redirect Target Directory

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RCargo is a high-performance wrapper around Rust's cargo that redirects the target directory to fast storage (typically RAM disk) to dramatically speed up compilation times and save your SSDs.

✨ Features

• 🚀 Per-project target directories: Each project gets its own isolated cache directory
• 🔧 Environment variable support: Customize cache location with RCARGO_TARGET_DIR
• 📊 Cache management: Built-in commands to view and clean cache
• 🔄 Cargo pass-through: All standard cargo commands work transparently
• 💾 Space-efficient: Easy cleanup of unused cache directories

🚀 Quick Start

Installation

# From source
git clone https://github.com/sakarie9/rcargo.git
cd rcargo
cargo install --path .

# Or directly from git
cargo install --git https://github.com/sakarie9/rcargo.git

Basic Usage

Use rcargo exactly like cargo, but your target will be put in specified directory, default to /tmp/rcargo_targets

set RCARGO_TARGET_DIR environment varibles to custom target directory.

💡 Tips

Replace cargo with rcargo

There are two convenient ways to make rcargo your default Rust build tool:

Method 1: Symbolic Link Approach

Configure rcargo to create a symbolic link named target in your project directory. This way, both cargo and rcargo will seamlessly use the same redirected target directory:

export RCARGO_TARGET_LINK_NAME=target

Note

If the symbolic link target directory doesn't exist, cargo commands will fail. You must run rcargo at least once to create the target directory before using the symbolic link approach.

Method 2: Shell Alias

Create an alias to automatically use rcargo whenever you type cargo:

alias cargo=rcargo

Add this line to your shell configuration file (.bashrc, .zshrc, etc.) to make it permanent.

📋 Commands

Standard Cargo Commands

All standard cargo commands work seamlessly:

rcargo build          # Build the project
rcargo test           # Run tests  
rcargo run            # Run the project
rcargo check          # Check for errors
rcargo clean          # Clean target directory (cargo's clean)

RCargo-Specific Commands

View Cache Sizes

# Show current project cache size
rcargo size

# Show all cached projects
rcargo size --all

Example output:

Current project 'my-app' target size: 125.4 MB

All cached project target directories:
  my-app-a1b2c3d: 125.4 MB
  web-server-x7y8z9: 89.2 MB  
  cli-tool-m4n5o6: 45.8 MB
Total cache size: 260.4 MB

Clean Cache

# Clean current project cache (with confirmation)
rcargo purge

# Clean all project caches (with confirmation)
rcargo purge --all

# Skip confirmation prompt
rcargo purge --yes
rcargo purge --all --yes

Version Information

# Shows both rcargo and cargo versions
rcargo --version

⚙️ Configuration

Environment Variables

Variable	Description	Default
RCARGO_CARGO_PATH	Custom cargo binary path	/usr/bin/cargo
RCARGO_TARGET_DIR	Custom target directory location	/tmp/rcargo_targets
RCARGO_NO_TARGET_LINK	Not create link to target	false
RCARGO_TARGET_LINK_NAME	Target link name in project root	target_rcargo

Examples

# Use custom cache directory
export RCARGO_TARGET_DIR="/mnt/ramdisk/cargo_cache"
rcargo build

# Use SSD for cache
export RCARGO_TARGET_DIR="/fast-ssd/cargo_cache" 
rcargo build

📁 Cache Directory Structure

RCargo creates unique cache directories using the format:

{project_name}-{path_hash}

Where:

• project_name: Extracted from Cargo.toml or directory name
• path_hash: 7-character MD5 hash of the project path

Example:

/tmp/rcargo_targets/
├── my-web-app-a1b2c3d/     # /home/user/projects/my-web-app
├── my-web-app-x7y8z9a/     # /home/user/work/my-web-app (different path)
└── cli-tool-m4n5o6p/       # /home/user/tools/cli-tool

This ensures projects with the same name but different locations get separate caches.