If you’ve tried running sudo cargo run only to see the error sudo: cargo: command not found, you’re not alone. This issue is a common stumbling block for Rust developers new to working with elevated permissions. This post will walk you through why this happens and the correct way to execute a Rust program with sudo.
Why sudo cargo run Doesn’t Work
The sudo command temporarily elevates privileges for the command it precedes. However, sudo also runs with a minimal environment configuration, which means it may not have access to user-specific binaries, including cargo installed via rustup. When you attempt sudo cargo run, sudo can’t find cargo because it’s installed in a directory not included in sudo‘s default environment path.
This results in the error:
sudo: cargo: command not foundThe Correct Way to Run a Rust Program with sudo
The recommended approach is to separate the build process from the execution:
- Build the program with
cargo build: You only need regular user permissions for this step.cargo build - Run the executable with
sudo: Locate the built executable, typically intarget/debug/ortarget/release/, and then usesudoto run it directly.
sudo ./target/debug/<program-name>This method ensures you only use sudo when absolutely necessary (during the program’s execution) rather than for the entire build process.
Why This Approach is Better
By building as a regular user, you avoid potential issues that could arise from sudo permissions, such as altered environment variables or elevated access to system files. Separating the build and run steps aligns with best practices and keeps your system safer and cleaner.
Wrapping Up
If you need to use sudo in a Rust program that interacts with system resources (e.g., USB devices, files outside your user directory), it’s best to:
- Build the program as a regular user.
- Run it with
sudoonly when executing the compiled binary.
With this approach, you avoid the pitfalls of sudo cargo run and keep your environment secure and organized.