Unable to build Substrate

Question

I'm trying to build Substrate (https://github.com/paritytech/substrate) after cloning it it with git clone. I'm in the root directory. What am I doing wrong?

Steps to reproduce:

First attempt:

1. rustup override set nightly-2022-10-20
2. cargo build

output:

cargo build
   Compiling proc-macro2 v1.0.46
   Compiling unicode-ident v1.0.1
[...]
[...]
[...]
   Compiling substrate-wasm-builder v5.0.0-dev (/home/amab/src/substrate/utils/wasm-builder)
   Compiling kitchensink-runtime v3.0.0-dev (/home/amab/src/substrate/bin/node/runtime)
error: failed to run custom build command for `kitchensink-runtime v3.0.0-dev (/home/amab/src/substrate/bin/node/runtime)`

Caused by:
  process didn't exit successfully: `/home/amab/src/substrate/target/debug/build/kitchensink-runtime-00f6a898772ead1c/build-script-build` (exit status: 1)
  --- stderr
  Rust WASM toolchain not installed, please install it!

  Further error information:
  ------------------------------------------------------------
     Compiling wasm-test v1.0.0 (/tmp/.tmpLkxJdw)
  error[E0463]: can't find crate for `std`
    |
    = note: the `wasm32-unknown-unknown` target may not be installed
    = help: consider downloading the target with `rustup target add wasm32-unknown-unknown`
    = help: consider building the standard library from source with `cargo build -Zbuild-std`

  error: requires `sized` lang_item

  For more information about this error, try `rustc --explain E0463`.
  error: could not compile `wasm-test` due to 2 previous errors
  ------------------------------------------------------------

warning: build failed, waiting for other jobs to finish...

Second attempt:

cargo build
   Compiling unicode-ident v1.0.1
   Compiling proc-macro2 v1.0.46
   Compiling syn v1.0.98
[...]
[...]
[...]
   Compiling sp-runtime-interface-test-wasm v2.0.0 (/home/amab/src/substrate/primitives/runtime-interface/test-wasm)
   Compiling sp-runtime-interface-test-wasm-deprecated v2.0.0 (/home/amab/src/substrate/primitives/runtime-interface/test-wasm-deprecated)
error: failed to run custom build command for `substrate-test-runtime v2.0.0 (/home/amab/src/substrate/test-utils/runtime)`

Caused by:
  process didn't exit successfully: `/home/amab/src/substrate/target/debug/build/substrate-test-runtime-6372ab7d70979471/build-script-build` (exit status: 1)
  --- stderr
  Rust WASM toolchain not installed, please install it!

  Further error information:
  ------------------------------------------------------------
     Compiling wasm-test v1.0.0 (/tmp/.tmpi729zK)
  error[E0463]: can't find crate for `std`
    |
    = note: the `wasm32-unknown-unknown` target may not be installed
    = help: consider downloading the target with `rustup target add wasm32-unknown-unknown`
    = help: consider building the standard library from source with `cargo build -Zbuild-std`

  error: requires `sized` lang_item

  For more information about this error, try `rustc --explain E0463`.
  error: could not compile `wasm-test` due to 2 previous errors
  ------------------------------------------------------------

warning: build failed, waiting for other jobs to finish...
error: failed to run custom build command for `kitchensink-runtime v3.0.0-dev (/home/amab/src/substrate/bin/node/runtime)`

Caused by:
  process didn't exit successfully: `/home/amab/src/substrate/target/debug/build/kitchensink-runtime-00f6a898772ead1c/build-script-build` (exit status: 1)
  --- stderr
  Rust WASM toolchain not installed, please install it!

  Further error information:
  ------------------------------------------------------------
     Compiling wasm-test v1.0.0 (/tmp/.tmpPESiBy)
  error[E0463]: can't find crate for `std`
    |
    = note: the `wasm32-unknown-unknown` target may not be installed
    = help: consider downloading the target with `rustup target add wasm32-unknown-unknown`
    = help: consider building the standard library from source with `cargo build -Zbuild-std`

  error: requires `sized` lang_item

  For more information about this error, try `rustc --explain E0463`.
  error: could not compile `wasm-test` due to 2 previous errors
  ------------------------------------------------------------

^Z  Building [=====================> ] 1154/1205: sp-runtime-interface-test-wasm-deprecated(build.rs), librocksdb-sys(build), sp-runtime-interface-test-wasm(build.rs)    

Answer 1

First follow the installation guide to be sure you set up the environment property.

Build the code:

cargo build

And run it:

cargo run -- --dev

If you want to run the tests and play with it:

cargo test --all --release

Follow this tutorial to Build a local blockchain running a Substrate template node.

Answer 2

rustup target add wasm32-unknown-unknown --toolchain nightly-2022-10-20
cargo +nightly-2022-10-20 run

or

rustup default nightly-2022-10-20
rustup target add wasm32-unknown-unknown
cargo run