# 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](https://github.com/foresterre/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:
1) 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](https://github.com/rust-lang/rust/issues/56971#issuecomment-527199391)
2) Build from individual [release manifests](https://static.rust-lang.org/manifests.txt)
* Requires parsing multiple documents
* Approx. one week delay after a new release
* Also has more specific toolchain information
* [source](https://github.com/rust-lang/rust/issues/56971#issuecomment-532783994)
3) Parse Rust in-repo [RELEASES.md](https://raw.githubusercontent.com/rust-lang/rust/master/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.