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Setup |
This page will guide you through the 2 steps needed to prepare a computer for CESS development. Since Substrate is built with the Rust programming language, the first thing you will need to do is prepare the computer for Rust development - these steps will vary based on the computer's operating system. Once Rust is configured, you will use its toolchains to interact with Rust projects; the commands for Rust's toolchains will be the same for all supported, Unix-based operating systems.
CESS development is easiest on Unix-based operating systems like macOS or Linux.
Use a terminal shell to execute the following commands:
sudo apt update
# May prompt for location information
sudo apt install -y git clang curl libssl-dev llvm libudev-devRun these commands from a terminal:
pacman -Syu --needed --noconfirm curl git clangRun these commands from a terminal:
sudo dnf update
sudo dnf install clang curl git openssl-develRun these commands from a terminal:
sudo zypper install clang curl git openssl-devel llvm-devel libudev-develNOTE: The Apple M1 ARM system on a chip is not very well supported yet by rust, and thus you very likely will run into build errors stemming from this.
Open the Terminal application and execute the following commands:
# Install Homebrew if necessary https://brew.sh/
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
# Make sure Homebrew is up-to-date, install openssl
brew update
brew install opensslNote: Native development of Substrate is not very well supported! It is highly recommended to use Windows Subsystem Linux (WSL) and follow the instructions for Ubuntu/Debian.
Please refer to the separate guide for native Windows development.
For most users you can run our script to automate the steps listed below:
curl https://getsubstrate.io -sSf | bash -s -- --fastIf this gives any errors, please follow the steps below to manually configure rust on your machine.
This guide uses rustup to help manage the Rust toolchain. First install and
configure rustup:
# Install
curl https://sh.rustup.rs -sSf | sh
# Configure
source ~/.cargo/envConfigure the Rust toolchain to default to the latest stable version, add nightly and the nightly wasm target:
rustup default stable
rustup update
rustup update nightly
rustup target add wasm32-unknown-unknown --toolchain nightlyTo see what Rust toolchain you are presently using, run:
rustup showThis will show something like this (Ubuntu example) output:
Default host: x86_64-unknown-linux-gnu
rustup home: /home/user/.rustup
installed toolchains
--------------------
stable-x86_64-unknown-linux-gnu (default)
nightly-2020-10-06-x86_64-unknown-linux-gnu
nightly-x86_64-unknown-linux-gnu
installed targets for active toolchain
--------------------------------------
wasm32-unknown-unknown
x86_64-unknown-linux-gnu
active toolchain
----------------
stable-x86_64-unknown-linux-gnu (default)
rustc 1.50.0 (cb75ad5db 2021-02-10)
As you can see above, the default toolchain is stable, and the
nightly-x86_64-unknown-linux-gnu toolchain as well as its wasm32-unknown-unknown target is installed.
You also see that nightly-2020-10-06-x86_64-unknown-linux-gnu is installed, but is not used unless explicitly defined as illustrated in the specify your nightly version
section.
Substrate uses WebAssembly (Wasm) to produce portable blockchain
runtimes. You will need to configure your Rust compiler to use
nightly builds to allow you to
compile Substrate runtime code to the Wasm target.
There are upstream issues in Rust that need to be resolved before all of Substrate can use the stable Rust toolchain - this is our tracking issue if you are curious as to why and how this may be resolved.
Developers who are building Substrate itself should always use the latest bug-free versions of Rust stable and nightly. This is because the Substrate codebase follows the tip of Rust nightly, which means that changes in Substrate often depend on upstream changes in the Rust nightly compiler. To ensure your Rust compiler is always up to date, you should run:
rustup update
rustup update nightly
rustup target add wasm32-unknown-unknown --toolchain nightlyIt may be necessary to occasionally rerun
rustup updateif a change in the upstream Substrate codebase depends on a new feature of the Rust compiler. When you do this, both your nightly and stable toolchains will be pulled to the most recent release, and for nightly, it is generally not expected to compile WASM without error (although it very often does). be sure to specify your nightly version if you get WASM build errors fromrustupand downgrade nightly as needed.
If you want to guarantee that your build works on your computer as you update Rust and other dependencies, you should use a specific Rust nightly version that is known to be compatible with the version of Substrate they are using; this version will vary from project to project and different projects may use different mechanisms to communicate this version to developers. For instance, the Polkadot client specifies this information in its release notes.
# Specify the specific nightly toolchain in the date below:
rustup install nightly-<yyyy-MM-dd>Now, configure the nightly version to work with the Wasm compilation target:
rustup target add wasm32-unknown-unknown --toolchain nightly-<yyyy-MM-dd>Use the WASM_BUILD_TOOLCHAIN environment variable to specify the Rust nightly version a Substrate
project should use for Wasm compilation:
WASM_BUILD_TOOLCHAIN=nightly-<yyyy-MM-dd> cargo build --releaseNote that this only builds the runtime with the specified nightly. The rest of project will be compiled with your default toolchain, i.e. the latest installed stable toolchain.
If your computer is configured to use the latest Rust nightly and you would like to downgrade to a specific nightly version, follow these steps:
rustup uninstall nightly
rustup install nightly-<yyyy-MM-dd>
rustup target add wasm32-unknown-unknown --toolchain nightly-<yyyy-MM-dd>Reference： here