Contributing to Rust: Bootstrapping the Rust Compiler (rustc)
Channel: Felix K
Date: 2022-11-04

This is a video that explains the steps for downloading and building your own local copy of the Rust programming language. It first shows the process to create an "off the shelf build", and then describes the ways you can modify that process in order to get better debugging instrumentation and faster turn-around times for your own local development of changes to the Rust compiler and standard library.

0:00 - Intro. What is Rust?
1:22 - The Rustc Dev Guide
2:33 - Git clone of Rust
4:45 - The `x`/`x.py` build script
6:04 - Blindly bootstrapping Rust with no config.toml
13:54 - The cost (in compute time) of a blind build
15:42 - Running the locally-built compiler
20:33 - Taking blinders off: Tailored configuration via `x.py setup`
24:04 - A peek at `config.toml.example`
25:52 - The `config.compiler.toml` profile
26:55 - Boostrapping Rust with the compiler config.toml profile
30:00 - The cost (in compute time) of a compiler-profile build
31:10 - Accessing debug instrumentation (`RUSTC_LOG`)
35:13 - Modifying your copy of `rustc` (edit a `debug!` statement)
37:13 - The cost (in compute time) of conservatively rebuilding standard library
39:46 - The cost (in compute time) of non-incremental rebuilds
41:00 - How to avoid rebuilding the standard library
46:21 - The (finally reasonable) cost of rebuilding just the compiler