# 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](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: ```sh ./x.py [flags] ``` This is how the documentation and examples assume you are running `x.py`. See the [rustc dev guide][rustcguidebuild] 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][rustcguidebuild]. [gettingstarted]: https://rustc-dev-guide.rust-lang.org/getting-started.html [rustcguidebuild]: https://rustc-dev-guide.rust-lang.org/building/how-to-build-and-run.html#what-is-xpy ## 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](https://llvm.org/docs/GettingStarted.html#host-c-toolchain-both-compiler-and-standard-library) * `ninja`, or GNU `make` 3.81 or later (Ninja is recommended, especially on Windows) * `cmake` version listed on [LLVM's documentation](https://llvm.org/docs/GettingStarted.html#software) * `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][sysllvm]. [sysllvm]: https://rustc-dev-guide.rust-lang.org/building/new-target.html#using-pre-built-llvm ## Building on a Unix-like system ### Build steps 1. Clone the [source] with `git`: ```sh git clone https://github.com/rust-lang/rust.git cd rust ``` [source]: https://github.com/rust-lang/rust 2. Configure the build settings: ```sh ./configure ``` If you plan to use `x.py install` to create an installation, you can either set `DESTDIR` environment variable to your custom directory path: ```bash export DESTDIR= ``` or set `prefix` and `sysconfdir` in the `[install]` section to your custom directory path: ```sh ./configure --set install.prefix= --set install.sysconfdir= ``` When the `DESTDIR` environment variable is present, the `prefix` and `sysconfdir` values are combined with the path from the `DESTDIR` environment variable. 3. Build and install: ```sh ./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`. [Cargo]: https://github.com/rust-lang/cargo ### 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. ```sh ./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: ```powershell 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`](https://www.java.com/en/download/help/path.html) from the Java documentation. [winget]: https://github.com/microsoft/winget-cli 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][msys2] can be used to easily build Rust on Windows: [msys2]: https://www.msys2.org/ 1. Download the latest [MSYS2 installer][msys2] and go through the installer. 2. Download and install [Git for Windows](https://git-scm.com/download/win). 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: ```sh # 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: ```sh 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. [Visual Studio]: https://visualstudio.microsoft.com/downloads/ (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: ```sh 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 bootstrap to use an older version. This can be done by manually calling the appropriate vcvars file before running the bootstrap. ```batch 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=` when invoking `x.py` commands, or by creating a `config.toml` file (as described in [Building on a Unix-like system](#building-on-a-unix-like-system)), and passing `--set build.build=` to `./configure`. ## Building Documentation If you'd like to build the documentation, it's almost the same: ```sh ./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.