Introduction

rustup installs The Rust Programming Language from the official release channels, enabling you to easily switch between stable, beta, and nightly compilers and keep them updated. It makes cross-compiling simpler with binary builds of the standard library for common platforms. And it runs on all platforms Rust supports.

Check out the Concepts chapter for an overview of how rustup works and some of the terminology it uses. The Installation chapter covers installing rustup and getting started.

The source code of rustup and this manual may be found at https://github.com/rust-lang/rustup. If you find a problem, check out the issue tracker.

Release notes for rustup may be found in the CHANGELOG.

Installation

Follow the instructions at https://www.rust-lang.org/tools/install. If that doesn't work for you there are other installation methods.

rustup installs rustc, cargo, rustup and other standard tools to Cargo's bin directory. On Unix it is located at $HOME/.cargo/bin and on Windows at %USERPROFILE%\.cargo\bin. This is the same directory that cargo install will install Rust programs and Cargo plugins.

This directory will be in your $PATH environment variable, which means you can run them from the shell without further configuration. Open a new shell and type the following:

rustc --version

If you see something like rustc 1.19.0 (0ade33941 2017-07-17) then you are ready to Rust. If you decide Rust isn't your thing, you can completely remove it from your system by running rustup self uninstall.

Choosing where to install

rustup allows you to customise your installation by setting the environment variables CARGO_HOME and RUSTUP_HOME before running the rustup-init executable. As mentioned in the Environment Variables section, RUSTUP_HOME sets the root rustup folder, which is used for storing installed toolchains and configuration options. CARGO_HOME contains cache files used by cargo.

Note that you will need to ensure these environment variables are always set and that CARGO_HOME/bin is in the $PATH environment variable when using the toolchain.

Installing nightly

If you specify the nightly channel when installing rustup, the rustup-init script will do a "forced" installation by default. A "forced" installation means it will install the nightly channel regardless of whether it might be missing components that you want. If you want to install rustup with the nightly channel, and ensure it has the components that you want, you will need to do this in two phases. For example, if you want to make a fresh installation of rustup and then install nightly along with clippy or miri, first install rustup without a toolchain:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --default-toolchain none -y

Next you can install nightly allowing rustup to downgrade until it finds the components you need:

rustup toolchain install nightly --allow-downgrade --profile minimal --component clippy

This can be used to great effect in CI, to get you a toolchain rapidly which meets your criteria.

Enable tab completion for Bash, Fish, Zsh, or PowerShell

rustup now supports generating completion scripts for Bash, Fish, Zsh, and PowerShell. See rustup help completions for full details, but the gist is as simple as using one of the following:

# Bash
$ rustup completions bash > ~/.local/share/bash-completion/completions/rustup

# Bash (macOS/Homebrew)
$ rustup completions bash > $(brew --prefix)/etc/bash_completion.d/rustup.bash-completion

# Fish
$ mkdir -p ~/.config/fish/completions
$ rustup completions fish > ~/.config/fish/completions/rustup.fish

# Zsh
$ rustup completions zsh > ~/.zfunc/_rustup

# PowerShell v5.0+
$ rustup completions powershell >> $PROFILE.CurrentUserCurrentHost
# or
$ rustup completions powershell | Out-String | Invoke-Expression

Note: you may need to restart your shell in order for the changes to take effect.

For zsh, you must then add the following line in your ~/.zshrc before compinit:

fpath+=~/.zfunc

Windows

rustup works the same on Windows as it does on Unix, but there are some special considerations for Rust developers on Windows. As mentioned on the Rust download page, there are two ABIs in use on Windows: the native (MSVC) ABI used by Visual Studio, and the GNU ABI used by the GCC toolchain. Which version of Rust you need depends largely on what C/C++ libraries you want to interoperate with: for interop with software produced by Visual Studio use the MSVC build of Rust; for interop with GNU software built using the MinGW/MSYS2 toolchain use the GNU build.

When targeting the MSVC ABI, Rust additionally requires an installation of Visual Studio 2013 (or later) or the Visual C++ Build Tools 2019 so rustc can use its linker. For Visual Studio, make sure to check the "C++ tools" and "Windows 10 SDK" option. No additional software installation is necessary for basic use of the GNU build.

By default rustup on Windows configures Rust to target the MSVC ABI, that is a target triple of either i686-pc-windows-msvc or x86_64-pc-windows-msvc depending on the CPU architecture of the host Windows OS. The toolchains that rustup chooses to install, unless told otherwise through the toolchain specification, will be compiled to run on that target triple host and will target that triple by default.

You can change this behavior with rustup set default-host or during installation.

For example, to explicitly select the 32-bit MSVC host:

$ rustup set default-host i686-pc-windows-msvc

Or to choose the 64 bit GNU toolchain:

$ rustup set default-host x86_64-pc-windows-gnu

Since the MSVC ABI provides the best interoperation with other Windows software it is recommended for most purposes. The GNU toolchain is always available, even if you don't use it by default. Just install it with rustup toolchain install:

$ rustup toolchain install stable-gnu

You don't need to switch toolchains to support all windows targets though; a single toolchain supports all four x86 windows targets:

$ rustup target add x86_64-pc-windows-msvc
$ rustup target add x86_64-pc-windows-gnu
$ rustup target add i686-pc-windows-msvc
$ rustup target add i686-pc-windows-gnu

See the Cross-compilation chapter for more details on specifying different targets with the same compiler.

Other installation methods

The primary installation method, as described at https://rustup.rs, differs by platform:

On Windows, download and run the rustup-init.exe built for i686-pc-windows-gnu target. In general, this is the build of rustup one should install on Windows. Despite being built against the GNU toolchain, the Windows build of rustup will install Rust for the MSVC toolchain if it detects that MSVC is installed. If you prefer to install GNU toolchains or x86_64 toolchains by default this can be modified at install time, either interactively or with the --default-host flag, or after installation via rustup set default-host.
On Unix, run curl https://sh.rustup.rs -sSf | sh in your shell. This downloads and runs rustup-init.sh, which in turn downloads and runs the correct version of the rustup-init executable for your platform.

rustup-init accepts arguments, which can be passed through the shell script. Some examples:

$ curl https://sh.rustup.rs -sSf | sh -s -- --help
$ curl https://sh.rustup.rs -sSf | sh -s -- --no-modify-path
$ curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly
$ curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain none
$ curl https://sh.rustup.rs -sSf | sh -s -- --profile minimal --default-toolchain nightly

If you prefer you can directly download rustup-init for the platform of your choice:

MSVC builds of rustup additionally require an installation of Visual Studio 2019 or the Visual C++ Build Tools 2019. For Visual Studio, make sure to check the "C++ tools" and "Windows 10 SDK" option. No additional software installation is necessary for basic use of the GNU build.

You can fetch an older version from https://static.rust-lang.org/rustup/archive/{rustup-version}/{target-triple}/rustup-init[.exe]

To install rustup from source, check out the git repository from https://github.com/rust-lang/rustup and run cargo run --release. Note that currently rustup only builds on nightly Rust, and that after installation the rustup toolchains will supersede any pre-existing toolchains by prepending ~/.cargo/bin to the PATH environment variable.

Package managers

Several Linux distributions package Rust, and you may wish to use the packaged toolchain, such as for distribution package development. You may also wish to use a rustup-managed toolchain such as nightly or beta. Normally, rustup will complain that you already have Rust installed in /usr and refuse to install. However, you can install Rust via rustup and have it coexist with your distribution's packaged Rust.

When you initially install Rust with rustup, pass the -y option to make it ignore the packaged Rust toolchain and install a rustup-managed toolchain into ~/.cargo/bin. Add that directory to your $PATH (or let rustup do it for you by not passing --no-modify-path). Then, to tell rustup about your system toolchain, run:

rustup toolchain link system /usr

You can then use "system" as a rustup toolchain, just like "nightly". For example, using the toolchain override shorthand, you can run cargo +system build to build with the system toolchain, or cargo +nightly build to build with nightly.

If you do distribution Rust development, you should likely make "system" your default toolchain:

rustup default system

Concepts

How rustup works

rustup is a toolchain multiplexer. It installs and manages many Rust toolchains and presents them all through a single set of tools installed to ~/.cargo/bin. The rustc and cargo executables installed in ~/.cargo/bin are proxies that delegate to the real toolchain. rustup then provides mechanisms to easily change the active toolchain by reconfiguring the behavior of the proxies.

So when rustup is first installed, running rustc will run the proxy in $HOME/.cargo/bin/rustc, which in turn will run the stable compiler. If you later change the default toolchain to nightly with rustup default nightly, then that same proxy will run the nightly compiler instead.

This is similar to Ruby's rbenv, Python's pyenv, or Node's nvm.

Terminology

channel — Rust is released to three different "channels": stable, beta, and nightly. See the Channels chapter for more details.
toolchain — A "toolchain" is a complete installation of the Rust compiler (rustc) and related tools (like cargo). A toolchain specification includes the release channel or version, and the host platform that the toolchain runs on.
target — rustc is capable of generating code for many platforms. The "target" specifies the platform that the code will be generated for. By default, cargo and rustc use the host toolchain's platform as the target. To build for a different target, usually the target's standard library needs to be installed first via the rustup target command. See the Cross-compilation chapter for more details.
component — Each release of Rust includes several "components", some of which are required (like rustc) and some that are optional (like clippy). See the Components chapter for more detail.
profile — In order to make it easier to work with components, a "profile" defines a grouping of components. See the Profiles chapter for more details.

Channels

Rust is released to three different "channels": stable, beta, and nightly. The stable releases are made every 6 weeks (with occasional point releases). Beta releases are the version that will appear in the next stable release. Nightly releases are made every night. See The Rust Book for more details on Rust's train release model. The release schedule is posted to the Rust Forge. rustup assists with installing different channels, keeping them up-to-date, and easily switching between them.

After a release channel has been installed, rustup can be used to update the installed version to the latest release on that channel. See the Keeping rust up to date section for more information.

rustup can also install specific versions of Rust, such as 1.45.2 or nightly-2020-07-27. See the Toolchains chapter for more information on installing different channels and releases. See the Overrides chapter for details on switching between toolchains and pinning your project to a specific toolchain.

Working with nightly Rust

rustup gives you easy access to the nightly compiler and its experimental features. To add it just run rustup toolchain install nightly:

$ rustup toolchain install nightly
info: syncing channel updates for 'nightly'
info: downloading toolchain manifest
info: downloading component 'rustc'
info: downloading component 'rust-std'
info: downloading component 'rust-docs'
info: downloading component 'cargo'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'rust-docs'
info: installing component 'cargo'

  nightly installed: rustc 1.9.0-nightly (02310fd31 2016-03-19)

Now Rust nightly is installed, but not activated. To test it out you can run a command from the nightly toolchain like

$ rustup run nightly rustc --version
rustc 1.9.0-nightly (02310fd31 2016-03-19)

But more likely you want to use it for a while. To switch to nightly globally, change the default with rustup default nightly:

$ rustup default nightly
info: using existing install for 'nightly'
info: default toolchain set to 'nightly'

  nightly unchanged: rustc 1.9.0-nightly (02310fd31 2016-03-19)

Now any time you run cargo or rustc you will be running the nightly compiler.

With nightly installed any time you run rustup update, the nightly channel will be updated in addition to stable:

$ rustup update
info: syncing channel updates for 'stable'
info: syncing channel updates for 'nightly'
info: checking for self-updates
info: downloading self-updates

   stable unchanged: rustc 1.7.0 (a5d1e7a59 2016-02-29)
  nightly unchanged: rustc 1.9.0-nightly (02310fd31 2016-03-19)

Nightly availability

Nightly toolchains may fail to build, so for any given date and target platform there may not be a toolchain available. Furthermore, nightly builds may be published with missing non-default components (such as clippy). As such, it can be difficult to find fully-working nightlies. Use the rustup-components-history project to find the build status of recent nightly toolchains and components.

When you attempt to install or update the nightly channel, rustup will check if a required or previously installed component is missing. If it is missing, rustup will automatically search for an older release that contains the required components. There are several ways to change this behavior:

Use the --force flag to rustup toolchain install to force it to install the most recent version even if there is a missing component.
Use the --profile flag to rustup toolchain install to use a different profile that does not contain the missing component. For example, --profile=minimal should always work, as the minimal set is required to exist. See the Profiles chapter for more detail.
Install a specific date that contains the components you need. For example, rustup toolchain install nightly-2020-07-27. You can then use overrides to pin to that specific release.

Toolchains

Many rustup commands deal with toolchains, a single installation of the Rust compiler. rustup supports multiple types of toolchains. The most basic track the official release channels: stable, beta and nightly; but rustup can also install toolchains from the official archives, for alternate host platforms, and from local builds.

Toolchain specification

Standard release channel toolchain names have the following form:

<channel>[-<date>][-<host>]

<channel>       = stable|beta|nightly|<major.minor>|<major.minor.patch>
<date>          = YYYY-MM-DD
<host>          = <target-triple>

'channel' is a named release channel, a major and minor version number such as 1.42, or a fully specified version number, such as 1.42.0. Channel names can be optionally appended with an archive date, as in nightly-2014-12-18, in which case the toolchain is downloaded from the archive for that date.

Finally, the host may be specified as a target triple. This is most useful for installing a 32-bit compiler on a 64-bit platform, or for installing the MSVC-based toolchain on Windows. For example:

$ rustup toolchain install stable-x86_64-pc-windows-msvc

For convenience, elements of the target triple that are omitted will be inferred, so the above could be written:

$ rustup toolchain install stable-msvc

Toolchain names that don't name a channel instead can be used to name custom toolchains.

Custom toolchains

For convenience of developers working on Rust itself, rustup can manage local builds of the Rust toolchain. To teach rustup about your build, run:

$ rustup toolchain link my-toolchain path/to/my/toolchain/sysroot

For example, on Ubuntu you might clone rust-lang/rust into ~/rust, build it, and then run:

$ rustup toolchain link myrust ~/rust/build/x86_64-unknown-linux-gnu/stage2/
$ rustup default myrust

Now you can name my-toolchain as any other rustup toolchain. Create a rustup toolchain for each of your rust-lang/rust workspaces and test them easily with rustup run my-toolchain rustc.

Because the rust-lang/rust tree does not include Cargo, when cargo is invoked for a custom toolchain and it is not available, rustup will attempt to use cargo from one of the release channels, preferring 'nightly', then 'beta' or 'stable'.

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.
cargo — Cargo is a package manager and build tool.
rustfmt — Rustfmt 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.
rls — RLS is a language server that provides support for editors and IDEs.
clippy — Clippy is a lint tool that provides extra checks for common mistakes and stylistic choices.
miri — Miri 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 RLS, 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-analysis — Metadata about the standard library, used by tools like RLS.
rust-mingw — This contains a linker and platform libraries for building on the x86_64-pc-windows-gnu platform.
llvm-tools-preview — This is an experimental component which 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.

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.

Profiles

rustup has the concept of "profiles". They are groups of components you can choose to download while installing a new Rust toolchain. The profiles available at this time are minimal, default, and complete:

The minimal profile includes as few components as possible to get a working compiler (rustc, rust-std, and cargo). It's recommended to use this component on Windows systems if you don't use local documentation (the large number of files can cause issues with some Antivirus systems), and in CI.
The default profile includes all of components in the minimal profile, and adds rust-docs, rustfmt, and clippy. This profile will be used by rustup by default, and it's the one recommended for general use.
The complete profile includes all the components available through rustup. This should never be used, as it includes every component ever included in the metadata and thus will almost always fail. If you are looking for a way to install devtools such as miri or IDE integration tools (rls), you should use the default profile and install the needed additional components manually, either by using rustup component add or by using -c when installing the toolchain.

To change the rustup profile you can use the rustup set profile command. For example, to select the minimal profile you can use:

rustup set profile minimal

It's also possible to choose the profile when installing rustup for the first time, either interactively by choosing the "Customize installation" option or programmatically by passing the --profile=<name> flag. Profiles will only affect newly installed toolchains: as usual it will be possible to install individual components later with: rustup component add.

Proxies

rustup provides a number of wrappers for common Rust tools. These are called proxies and represent commands which are provided by the various components.

The list of proxies is currently static in rustup and is as follows:

rustc is the compiler for the Rust programming language, provided by the project itself and comes from the rustc component.
rustdoc is a tool distributed in the rustc component which helps you to generate documentation for Rust projects.
cargo is the Rust package manager which downloads your Rust package’s dependencies, compiles your packages, makes distributable packages, and uploads them to crates.io (the Rust community’s package registry). It comes from the cargo component.
rust-lldb and rust-gdb are simple wrappers around the lldb and gdb debuggers respectively. The wrappers enable some pretty-printing of Rust values and add some convenience features to the debuggers by means of their scripting interfaces.
rls is part of the Rust IDE integration tooling. It implements the language-server protocol to permit IDEs and editors such as Visual Studio Code, ViM, or Emacs, access to the semantics of the Rust code you are editing. It comes from the rls component.
cargo-clippy and clippy-driver are related to the clippy linting tool which provides extra checks for common mistakes and stylistic choices and it comes from the clippy component.
cargo-miri is an experimental interpreter for Rust's mid-level intermediate representation (MIR) and it comes from the miri component.

Basic usage

The rustup command-line has a built-in help system that provides more information about each command. Run rustup help for an overview. Detailed help for each subcommand is also available. For example, run rustup toolchain install --help for specifics on installing toolchains.

Keeping Rust up to date

Rust is distributed on three different release channels: stable, beta, and nightly. rustup is configured to use the stable channel by default, which represents the latest release of Rust, and is released every six weeks.

When a new version of Rust is released, you can type rustup update to update to it:

$ rustup update
info: syncing channel updates for 'stable'
info: downloading component 'rustc'
info: downloading component 'rust-std'
info: downloading component 'rust-docs'
info: downloading component 'cargo'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'rust-docs'
info: installing component 'cargo'
info: checking for self-updates
info: downloading self-updates

  stable updated: rustc 1.7.0 (a5d1e7a59 2016-02-29)

This is the essence of rustup.

Keeping rustup up to date

Running rustup update also checks for updates to rustup and automatically installs the latest version. To manually check for updates and install the latest version of rustup without updating installed toolchains type rustup self update:

$ rustup self update
info: checking for self-updates
info: downloading self-updates

Note: rustup will automatically update itself at the end of any toolchain installation as well. You can prevent this automatic behaviour by passing the --no-self-update argument when running rustup update or rustup toolchain install.

Overrides

rustup automatically determines which toolchain to use when one of the installed commands like rustc is executed. There are several ways to control and override which toolchain is used:

A toolchain override shorthand used on the command-line, such as cargo +beta.
The RUSTUP_TOOLCHAIN environment variable.
A directory override, set with the rustup override command.
The rust-toolchain file.
The default toolchain.

The toolchain is chosen in the order listed above, using the first one that is specified. There is one exception though: directory overrides and the rust-toolchain file are also preferred by their proximity to the current directory. That is, these two override methods are discovered by walking up the directory tree toward the filesystem root, and a rust-toolchain file that is closer to the current directory will be preferred over a directory override that is further away.

To verify which toolchain is active use rustup show.

Toolchain override shorthand

The rustup toolchain proxies can be instructed directly to use a specific toolchain, a convenience for developers who often test different toolchains. If the first argument to cargo, rustc or other tools in the toolchain begins with +, it will be interpreted as a rustup toolchain name, and that toolchain will be preferred, as in

cargo +beta test

Directory overrides

Directories can be assigned their own Rust toolchain with rustup override. When a directory has an override then any time rustc or cargo is run inside that directory, or one of its child directories, the override toolchain will be invoked.

To use to a specific nightly for a directory:

rustup override set nightly-2014-12-18

Or a specific stable release:

rustup override set 1.0.0

To see the active toolchain use rustup show. To remove the override and use the default toolchain again, rustup override unset.

The per-directory overrides are stored in a configuration file in rustup's home directory.

The toolchain file

Some projects find themselves 'pinned' to a specific release of Rust and want this information reflected in their source repository. This is most often the case for nightly-only software that pins to a revision from the release archives.

In these cases the toolchain can be named in the project's directory in a file called rust-toolchain, the content of which is either the name of a single rustup toolchain, or a TOML file with the following layout:

[toolchain]
channel = "nightly-2020-07-10"
components = [ "rustfmt", "rustc-dev" ]
targets = [ "wasm32-unknown-unknown", "thumbv2-none-eabi" ]

If the TOML format is used, the [toolchain] section is mandatory, and at least one property must be specified.

The rust-toolchain file is suitable to check in to source control. This file has to be encoded in US-ASCII (if you are on Windows, check the encoding and that it does not starts with a BOM).

The toolchains named in this file have a more restricted form than rustup toolchains generally, and may only contain the names of the three release channels, 'stable', 'beta', 'nightly', Rust version numbers, like '1.0.0', and optionally an archive date, like 'nightly-2017-01-01'. They may not name custom toolchains, nor host-specific toolchains.

Default toolchain

If no other overrides are set, the global default toolchain will be used. This default can be chosen when rustup is installed. The rustup default command can be used to set and query the current default. Run rustup default without any arguments to print the current default. Specify a toolchain as an argument to change the default:

rustup default nightly-2020-07-27

Cross-compilation

Rust supports a great number of platforms. For many of these platforms The Rust Project publishes binary releases of the standard library, and for some the full compiler. rustup gives easy access to all of them.

When you first install a toolchain, rustup installs only the standard library for your host platform - that is, the architecture and operating system you are presently running. To compile to other platforms you must install other target platforms. This is done with the rustup target add command. For example, to add the Android target:

$ rustup target add arm-linux-androideabi
info: downloading component 'rust-std' for 'arm-linux-androideabi'
info: installing component 'rust-std' for 'arm-linux-androideabi'

With the arm-linux-androideabi target installed you can then build for Android with Cargo by passing the --target flag, as in cargo build --target=arm-linux-androideabi.

Note that rustup target add only installs the Rust standard library for a given target. There are typically other tools necessary to cross-compile, particularly a linker. For example, to cross compile to Android the Android NDK must be installed. In the future, rustup will provide assistance installing the NDK components as well.

To install a target for a toolchain that isn't the default toolchain use the --toolchain argument of rustup target add, like so:

$ rustup target add --toolchain <toolchain> <target>...

To see a list of available targets, rustup target list. To remove a previously-added target, rustup target remove.

Environment variables

RUSTUP_HOME (default: ~/.rustup or %USERPROFILE%/.rustup) Sets the root rustup folder, used for storing installed toolchains and configuration options.
RUSTUP_TOOLCHAIN (default: none) If set, will override the toolchain used for all rust tool invocations. A toolchain with this name should be installed, or invocations will fail.
RUSTUP_DIST_SERVER (default: https://static.rust-lang.org) Sets the root URL for downloading static resources related to Rust. You can change this to instead use a local mirror, or to test the binaries from the staging directory.
RUSTUP_DIST_ROOT (default: https://static.rust-lang.org/dist) Deprecated. Use RUSTUP_DIST_SERVER instead.
RUSTUP_UPDATE_ROOT (default https://static.rust-lang.org/rustup) Sets the root URL for downloading self-updates.
RUSTUP_IO_THREADS unstable (defaults to reported cpu count). Sets the number of threads to perform close IO in. Set to 1 to force single-threaded IO for troubleshooting, or an arbitrary number to override automatic detection.
RUSTUP_TRACE_DIR unstable (default: no tracing) Enables tracing and determines the directory that traces will be written too. Traces are of the form PID.trace. Traces can be read by the Catapult project tracing viewer.
RUSTUP_UNPACK_RAM unstable (default free memory or 500MiB if unable to tell, min 210MiB) Caps the amount of RAM rustup will use for IO tasks while unpacking.
RUSTUP_NO_BACKTRACE Disables backtraces on non-panic errors even when RUST_BACKTRACE is set.
RUSTUP_PERMIT_COPY_RENAME unstable When set, allows rustup to fall-back to copying files if attempts to rename result in an cross-device link errors. These errors occur on OverlayFS, which is used by Docker. This feature sacrifices some transactions protections and may be removed at any point. Linux only.

Configuration

Rustup has a settings file in TOML format at ${RUSTUP_HOME}/settings.toml. The schema for this file is not part of the public interface for rustup - the rustup CLI should be used to query and set settings.

On Unix operating systems a fallback settings file is consulted for some settings. This fallback file is located at /etc/rustup/settings.toml and currently can define only default_toolchain.

Network proxies

Enterprise networks often don't have direct outside HTTP access, but enforce the use of proxies. If you're on such a network, you can request that rustup uses a proxy by setting its URL in the environment. In most cases, setting https_proxy should be sufficient. On a Unix-like system with a shell like bash or zsh, you could use:

export https_proxy=socks5://proxy.example.com:1080 # or http://proxy.example.com:8080

On Windows, the command would be:

set https_proxy=socks5://proxy.example.com:1080

If you need a more complex setup, rustup supports the convention used by the curl program, documented in the ENVIRONMENT section of its manual page.

The use of curl is presently deprecated, however it can still be used by providing the RUSTUP_USE_CURL environment variable, for example:

RUSTUP_USE_CURL=1 rustup update

Note that some versions of libcurl apparently require you to drop the http:// or https:// prefix in environment variables. For example, export http_proxy=proxy.example.com:1080 (and likewise for HTTPS). If you are getting an SSL unknown protocol error from rustup via libcurl but the command-line curl command works fine, this may be the problem.

Examples

Command	Description
`rustup default nightly`	Set the default toolchain to the latest nightly
`rustup set profile minimal`	Set the default profile
`rustup target list`	List all available targets for the active toolchain
`rustup target add arm-linux-androideabi`	Install the Android target
`rustup target remove arm-linux-androideabi`	Remove the Android target
`rustup run nightly rustc foo.rs`	Run the nightly regardless of the active toolchain
`rustc +nightly foo.rs`	Shorthand way to run a nightly compiler
`rustup run nightly bash`	Run a shell configured for the nightly compiler
`rustup default stable-msvc`	On Windows, use the MSVC toolchain instead of GNU
`rustup override set nightly-2015-04-01`	For the current directory, use a nightly from a specific date
`rustup toolchain link my-toolchain "C:\RustInstallation"`	Install a custom toolchain by symlinking an existing installation
`rustup show`	Show which toolchain will be used in the current directory
`rustup toolchain uninstall nightly`	Uninstall a given toolchain
`rustup toolchain help`	Show the `help` page for a subcommand (like `toolchain`)
`rustup man cargo`	(Unix only) View the man page for a given command (like `cargo`)

Security

rustup is secure enough for most people, but it still needs work. rustup performs all downloads over HTTPS, but does not yet validate signatures of downloads.

File modes on installation honor umask as of 1.18.4, use umask if very tight controls are desired.

If you wish to report a security issue, please follow the Rust security policy.

The rustup book