Components

Each toolchain has several “components”, some of which are required (like rustc) and some that are optional (like clippy). The rustup component command is used to manage the installed components. For example, run rustup component list to see a list of available and installed components.

Components can be added when installing a toolchain with the --component flag. For example:

rustup toolchain install nightly --component rust-docs

Components can be added to an already-installed toolchain with the rustup component command:

rustup component add rust-docs

To make it easier to choose which components are installed, rustup has the concept of “profiles” which provide named groupings of different components. See the Profiles chapter for more detail.

Most components have a target-triple suffix, such as rustc-x86_64-apple-darwin, to signify the platform the component is for.

The set of available components may vary with different releases and toolchains. The following is an overview of the different components:

  • rustc — The Rust compiler and Rustdoc.
  • cargoCargo is a package manager and build tool.
  • rustfmtRustfmt is a tool for automatically formatting code.
  • rust-std — This is the Rust standard library. There is a separate rust-std component for each target that rustc supports, such as rust-std-x86_64-pc-windows-msvc. See the Cross-compilation chapter for more detail.
  • rust-docs — This is a local copy of the Rust documentation. Use the rustup doc command to open the documentation in a web browser. Run rustup doc --help for more options.
  • rust-analyzerrust-analyzer is a language server that provides support for editors and IDEs.
  • clippyClippy is a lint tool that provides extra checks for common mistakes and stylistic choices.
  • miriMiri is an experimental Rust interpreter, which can be used for checking for undefined-behavior.
  • rust-src — This is a local copy of the source code of the Rust standard library. This can be used by some tools, such as rust-analyzer, to provide auto-completion for functions within the standard library; Miri which is a Rust interpreter; and Cargo’s experimental build-std feature, which allows you to rebuild the standard library locally.
  • rust-mingw — This contains a linker and platform libraries for building on the x86_64-pc-windows-gnu platform.
  • llvm-tools — This component contains a collection of LLVM tools.
  • rustc-dev — This component contains the compiler as a library. Most users will not need this; it is only needed for development of tools that link to the compiler, such as making modifications to Clippy.

Previous components

These components have been deprecated and are not published in new Rust releases.

  • rlsRLS is a language server that is deprecated and has been replaced by rust-analyzer.
  • rust-analysis — Metadata about the standard library, used by RLS.

Component availability

Not all components are available for all toolchains. Especially on the nightly channel, some components may not be included if they are in a broken state. The current status of all the components may be found on the rustup components history page. See the Nightly availability section for more details.