Rustfmt: Installation instructions outdated

[Julian-Wollersberger]

I tried installing rustfmt, but the installation instructions in the README.md seem outdated and I couldn't figure out how to install rustfmt correctly.
I tried:

$ cargo install rustfmt
error: binary `cargo-fmt` already exists in destination
binary `rustfmt` already exists in destination
Add --force to overwrite

This is the first time I tried using rustfmt. Is is normally preinstalled?
(I also tried installing with --force)

$ cargo fmt
error: 'cargo-fmt' is not installed for the toolchain 'stable-x86_64-unknown-linux-gnu'
To install, run `rustup component add rustfmt`
$ rustup component add rustfmt
error: toolchain 'stable-x86_64-unknown-linux-gnu' does not contain component 'rustfmt' for target 'x86_64-unknown-linux-gnu'

At least the error message tried ^^

$ rustup install nightly
$ cargo +nightly install --force rustfmt
$ cargo +nightly fmt
This version of rustfmt is deprecated. Use rustfmt-nightly. Use --force to run deprecated rustfmt.

Aparrently, I installed the wrong version. But:

$ rustup component add rustfmt --toolchain nightly
info: component 'rustfmt' for target 'x86_64-unknown-linux-gnu' is up to date

My setup:

Linux (Ubuntu 18.04)
rustup 1.16.0 (beab5ac2b 2018-12-06)
rustc 1.31.1 (b6c32da9b 2018-12-18)
cargo 1.31.0 (339d9f9c8 2018-11-16)

Can someone correct the installation instructions in the README.md? Thank you ^^

[Julian-Wollersberger]

I was able to figure it out myself :)
Aparrently the right command was

cargo +nightly install --force rustfmt-nightly

And it can be used with cargo fmt, the +nightly isn't necessary.

[nrc]

You should use rustup component add rustfmt which is what is in the README. I think you might be looking at an old version of the readme.

[ZaneA]

Sorry to reopen but I've run into this as well, rustup component add rustfmt doesn't appear to work for me:

$ rustup --version
rustup 1.16.0 (beab5ac2b 2018-12-06)
$ rustc --version
rustc 1.31.1 (b6c32da9b 2018-12-18)
$ rustup component add rustfmt
error: toolchain 'stable-x86_64-unknown-linux-gnu' does not contain component 'rustfmt' for target 'x86_64-unknown-linux-gnu'

I had done a rustup update earlier today to get to 1.31 and didn't have rustfmt installed previously.

[nrc]

You might need to do rustup self update, its also possibly a bug in Rustup

[ZaneA]

Thank you, it does appear to be a bug in Rustup, the solution at https://github.com/rust-lang/rustup.rs/issues/1558#issuecomment-452110409 solved the problem for me:

rustup toolchain remove stable && rustup toolchain install stable