rust-lang / rust-lang/rust

bootstrap: have a flag to switch stage0 alt build

Open
#161,856 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

C-feature-request needs-triage P-low T-bootstrap
Dominant language
Rust
Stars
119k
Forks
16.1k
PR merge metrics
PR metrics pending

Description

When diagnosing bootstrap problems, it would be useful to have an easy way to switch stage0 to an "alt" build for debugging purposes (enabling debug assertions for llvm)

After a bit of digging I found that I could do that by setting artifacts_server=https://ci-artifacts.rust-lang.org/rustc-builds-alt
in src/stage0 and running ./x.py run src/tools/bump-stage0
but some kind of rustc.bootstrap=alt flag in bootstrap.toml which does this automatically during build might be more convenient.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reading the stage0 configuration in src/stage0 and the bootstrap.toml handling, then trace the existing ./x.py run src/tools/bump-stage0 flow. Add a rustc.bootstrap=alt option that selects the rustc-builds-alt artifacts server automatically. Done means a build using the flag switches stage0 to the alternate build without manually editing src/stage0.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
build-system, compilers
Issue type
Feature
Difficulty
3/5
Estimated time
1-2 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
68/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.