Stabilize cargo-script

Summary

Stabilize support for “cargo script”, the ability to have a single file that contains both Rust code and a Cargo.toml.

Motivation

Being able to have a Cargo package in a single file can reduce friction in development and communication, improving bug reports, educational material, prototyping, and development of small utilities.

The status quo

Today, at minimum a Cargo package is at least two files (Cargo.toml and either main.rs or lib.rs). The Cargo.toml has several required fields.

To share this in a bug report, people resort to

• Creating a repo and sharing it
• A shell script that cats out to multiple files
• Manually specifying each file
• Under-specifying the reproduction case (likely the most common due to being the easiest)

To create a utility, a developer will need to run cargo new, update the Cargo.toml and main.rs, and decide on a strategy to run this (e.g. a shell script in the path that calls cargo run --manifest-path ...).

Cargo has had unstable Cargo script support for years. New, unstable syntax has been added and gone through rounds of testing. A stabilization report exists for frontmatter syntax but work is needed to finish going through that process and then on Cargo’s side.

The next 6 months

Work with T-lang, T-cargo, and other affected teams as we go through the stabilization process.

The “shiny future” we are working towards

Team asks

Frequently asked questions