Live documentation lists feature(s) not yet in release

[ickk]

Problem

The live documentation says it should be possible to use a rust-toolchain.toml file, however it seems that was only added in #2653 which is more recent than the latest release.

Steps

Check the version of rustup installed

PS D:\> rustup --version
rustup 1.23.1 (3df2264a9 2020-11-30)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.51.0 (2fd73fabe 2021-03-23)`

Create a new project and create a rust-toolchain.toml file with a nightly toolchain:

PS D:\> cargo new dir; cd dir
Created binary (application) `dir` package
PS D:\dir> Set-Content -Path rust-toolchain.toml -Value "[toolchain]`nchannel = `"nightly`"`n"
PS D:\dir> Get-Content .\rust-toolchain.toml
[toolchain]
channel = "nightly"

Sanity check there is no rust-toolchain file:

PS D:\dir> Test-Path -Path rust-toolchain
False

Check which toolchain rustup recognises as active. Note that it is not the toolchain listed in the rust-toolchain.toml file we just created:

PS D:\dir> rustup show
Default host: x86_64-pc-windows-msvc
rustup home:  C:\Users\Nick\.rustup

installed toolchains
--------------------

stable-i686-pc-windows-msvc
stable-x86_64-pc-windows-msvc (default)
nightly-x86_64-pc-windows-msvc

active toolchain
----------------

stable-x86_64-pc-windows-msvc (default)
rustc 1.51.0 (2fd73fabe 2021-03-23)

Rustup does set the correct toolchain if we use a rust-toolchain file instead of the .toml file:

PS D:\dir> Set-Content -Path rust-toolchain -Value "[toolchain]`nchannel = `"nightly`"`n"
PS D:\dir> Test-Path -Path rust-toolchain
True
PS D:\dir> rustup show
Default host: x86_64-pc-windows-msvc
rustup home:  C:\Users\Nick\.rustup

installed toolchains
--------------------

stable-i686-pc-windows-msvc
stable-x86_64-pc-windows-msvc (default)
nightly-x86_64-pc-windows-msvc

active toolchain
----------------

nightly-x86_64-pc-windows-msvc (overridden by '\\?\D:\dir\rust-toolchain')
rustc 1.53.0-nightly (07e0e2ec2 2021-03-24)

Possible Solution(s)
Either bring the documentation in line with the behaviour of rustup, or bring rustup in line with the documentation.

Note: #2665 mentions that only changes to documentation on the stable branch should be live (linked to from rustup.rs), so perhaps the documentation on the stable branch could be kept in line with the latest release?

[ehuss]

Hm, looks like 1.24 got merged to the stable branch, but wasn't released? Perhaps kinnison can clarify.

[rbtcollins]

We were going to release but it was the same week as a rust release, and didn't want to collide with the possibility of bugs.

[kinnison]

Yeah this is awkward - I staged a release and then realised we were going to collide with a toolchain release. And since then there's been more done which I'd like to include in 1.24 so I'll be re-staging a release at some point pretty soon with a view to releasing assuming all is well.

[kinnison]

1.24.1 has now been released and hopefully won't need to be withdrawn.