Manifesta
Introduction
The Rust programming language uses deterministic versioning for toolchain releases. Stable versions use SemVer, while nightly, beta and historical builds can be accessed by using dated builds (YY-MM-DD).
cargo-msrv is a tool which can be used to determine the minimal supported Rust version (MSRV). In cargo-msrv I started by parsing the latest channel manifest, and then decreasing the minor semver version. This is not great for many reasons:
- Except for the latest released version, we are left guessing the decreased version numbers actually exist
- Only stable versions are supported, not nightly, beta, or other channels
- Only 1.x.0 versions are supported
As a result of the above limitations, I decided to look for an actual index of releases. After doing some research I found the following options:
- Use the AWS index (e.g.
aws --no-sign-request s3 ls static-rust-lang-org/dist/ > dist.txt)- Rate-limited (only obtaining the index took ~40 seconds)
- source
- Build from individual release manifests
- Requires parsing multiple documents
- Approx. one week delay after a new release
- Also has more specific toolchain information
- source
- Parse Rust in-repo RELEASES.md
- Note: stable only
Each of these options requires additional parsing, which is where this crate comes in: this crate provides an index of all Rust releases. It will eventually support all three options, but initially, only the second one will be supported.
Technical options
- Bring your own download tool (planned, will be a cfg option in the future)
- Optionally, use built in download tool
Crate name
Portmanteau of "manifest", referring to the Rust release manifests this crate pulls its (meta)data from and "festa", Portuguese for party.