rust/INSTALL.md

Installing from Source

Note: This document describes building Rust from source. This is not recommended if you don't know what you're doing. If you just want to install Rust, check out the README.md instead.

The Rust build system uses a Python script called x.py to build the compiler, which manages the bootstrapping process. It lives at the root of the project. It also uses a file named config.toml to determine various configuration settings for the build. You can see a full list of options in config.example.toml.

The x.py command can be run directly on most Unix systems in the following format:

./x.py <subcommand> [flags]

This is how the documentation and examples assume you are running x.py. See the rustc dev guide if this does not work on your platform.

More information about x.py can be found by running it with the --help flag or reading the rustc dev guide.

Dependencies

Make sure you have installed the dependencies:

• python 3 or 2.7
• git
• A C compiler (when building for the host, cc is enough; cross-compiling may need additional compilers)
• curl (not needed on Windows)
• pkg-config if you are compiling on Linux and targeting Linux
• libiconv (already included with glibc on Debian-based distros)

To build Cargo, you'll also need OpenSSL (libssl-dev or openssl-devel on most Unix distros).

If building LLVM from source, you'll need additional tools:

• g++, clang++, or MSVC with versions listed on LLVM's documentation
• ninja, or GNU make 3.81 or later (Ninja is recommended, especially on Windows)
• cmake 3.13.4 or later
• libstdc++-static may be required on some Linux distributions such as Fedora and Ubuntu

On tier 1 or tier 2 with host tools platforms, you can also choose to download LLVM by setting llvm.download-ci-llvm = true. Otherwise, you'll need LLVM installed and llvm-config in your path. See the rustc-dev-guide for more info.

Building on a Unix-like system

Build steps

1. Clone the source with git:

   git clone https://github.com/rust-lang/rust.git
   cd rust
   

2. Configure the build settings:

   ./configure
   

   If you plan to use x.py install to create an installation, it is recommended that you set the prefix value in the [install] section to a directory: ./configure --set install.prefix=<path>

3. Build and install:

   ./x.py build && ./x.py install
   

   When complete, ./x.py install will place several programs into $PREFIX/bin: rustc, the Rust compiler, and rustdoc, the API-documentation tool. By default, it will also include Cargo, Rust's package manager. You can disable this behavior by passing --set build.extended=false to ./configure.

Configure and Make

This project provides a configure script and makefile (the latter of which just invokes x.py). ./configure is the recommended way to programmatically generate a config.toml. make is not recommended (we suggest using x.py directly), but it is supported and we try not to break it unnecessarily.

./configure
make && sudo make install

configure generates a config.toml which can also be used with normal x.py invocations.

Building on Windows

On Windows, we suggest using winget to install dependencies by running the following in a terminal:

winget install -e Python.Python.3
winget install -e Kitware.CMake
winget install -e Git.Git

Then edit your system's PATH variable and add: C:\Program Files\CMake\bin. See this guide on editing the system PATH from the Java documentation.

There are two prominent 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. Use the MSVC build of Rust to interop with software produced by Visual Studio and the GNU build to interop with GNU software built using the MinGW/MSYS2 toolchain.

MinGW

MSYS2 can be used to easily build Rust on Windows:

1. Download the latest MSYS2 installer and go through the installer.

2. Download and install Git for Windows. Make sure that it's in your Windows PATH. To enable access to it from within MSYS2, edit the relevant mingw[32|64].ini file in your MSYS2 installation directory and uncomment the line MSYS2_PATH_TYPE=inherit.

   You could install and use MSYS2's version of git instead with pacman, however this is not recommended as it's excruciatingly slow, and not frequently tested for compatibility.

3. Start a MINGW64 or MINGW32 shell (depending on whether you want 32-bit or 64-bit Rust) either from your start menu, or by running mingw64.exe or mingw32.exe from your MSYS2 installation directory (e.g. C:\msys64).

4. From this terminal, install the required tools:

   # Update package mirrors (may be needed if you have a fresh install of MSYS2)
   pacman -Sy pacman-mirrors
   
   # Install build tools needed for Rust. If you're building a 32-bit compiler,
   # then replace "x86_64" below with "i686". 
   # Note that it is important that you do **not** use the 'python2', 'cmake',
   # and 'ninja' packages from the 'msys2' subsystem.
   # The build has historically been known to fail with these packages.
   pacman -S make \
               diffutils \
               tar \
               mingw-w64-x86_64-python \
               mingw-w64-x86_64-cmake \
               mingw-w64-x86_64-gcc \
               mingw-w64-x86_64-ninja
   

5. Navigate to Rust's source code (or clone it), then build it:

   python x.py setup dist && python x.py build && python x.py install
   

If you want to try the native Windows versions of Python or CMake, you can remove them from the above pacman command and install them from another source. Follow the instructions in step 2 to get them on PATH.

Using Windows native Python can be helpful if you get errors when building LLVM. You may also want to use Git for Windows, as it is often much faster. Turning off real-time protection in the Windows Virus & Threat protections settings can also help with long run times (although note that it will automatically turn itself back on after some time).

MSVC

MSVC builds of Rust additionally require an installation of Visual Studio 2017 (or later) so rustc can use its linker. The simplest way is to get Visual Studio, check the "C++ build tools" and "Windows 10 SDK" workload.

(If you're installing CMake yourself, be careful that "C++ CMake tools for Windows" doesn't get included under "Individual components".)

With these dependencies installed, you can build the compiler in a cmd.exe shell with:

python x.py setup user
python x.py build

Right now, building Rust only works with some known versions of Visual Studio. If you have a more recent version installed and the build system doesn't understand, you may need to force rustbuild to use an older version. This can be done by manually calling the appropriate vcvars file before running the bootstrap.

CALL "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat"
python x.py build

Specifying an ABI

Each specific ABI can also be used from either environment (for example, using the GNU ABI in PowerShell) by using an explicit build triple. The available Windows build triples are:

• GNU ABI (using GCC)
  • i686-pc-windows-gnu
  • x86_64-pc-windows-gnu
• The MSVC ABI
  • i686-pc-windows-msvc
  • x86_64-pc-windows-msvc

The build triple can be specified by either specifying --build=<triple> when invoking x.py commands, or by creating a config.toml file (as described in Building on a Unix-like system), and passing --set build.build=<triple> to ./configure.

Building Documentation

If you'd like to build the documentation, it's almost the same:

./x.py doc

The generated documentation will appear under doc in the build directory for the ABI used. That is, if the ABI was x86_64-pc-windows-msvc, the directory will be build\x86_64-pc-windows-msvc\doc.

Notes

Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier stage of development). As such, source builds require an Internet connection to fetch snapshots, and an OS that can execute the available snapshot binaries.

See https://doc.rust-lang.org/nightly/rustc/platform-support.html for a list of supported platforms. Only "host tools" platforms have a pre-compiled snapshot binary available; to compile for a platform without host tools you must cross-compile.

You may find that other platforms work, but these are our officially supported build environments that are most likely to work.