I was trying to run the following command:
$ cargo +nightly install [package]
error: no such subcommand: `+nightly`
But … that didn’t work. This was my fix:
Remove Rust/Cargo from default package manager
I first removed the cargo package I had installed via apt from my system:
$ apt remove rustc rust-gdb libstd-rust-dev libstd-rust-1.43
This was on a rather old Ubuntu 18.04 LTS, so it had an outdated version of Rust/Cargo. To see which Rust packages you have installed, try this:
$ dpkg -l | grep -i rust
And see what packages come up with the name “rust” in them.
Install latest cargo release
From the official docs:
$ curl https://sh.rustup.rs -sSf | sh
Almost there!
Install package dependencies
But it still didn’t work straight away:
$ cargo +nightly install [package]
error: toolchain 'nightly-x86_64-unknown-linux-gnu' is not installed
Almost there! First, install the nightly toolchain using rustup (which is now installed, thanks to the installer we ran above):
$ rustup toolchain install nightly
[...]
nightly-x86_64-unknown-linux-gnu installed - rustc 1.50.0-nightly (a0d664bae 2020-11-22)
Now, the +nightly package install works:
$ cargo +nightly install [package]
[...]
Compiling rustc-hex v2.1.0
Compiling fake_instant v0.4.0
Compiling ansi_term v0.11.0
Compiling gimli v0.23.0
Compiling urlencoding v1.1.1
...
Building [=============> ] 107/411: ipnet, humantime, parity-wasm, object
(Note: I had to install pkg-config first before the cargo install could compile the package.)