Rust for Linux integration tests

Rust for Linux (RfL) is an effort for adding support for the Rust programming language into the Linux kernel.

Building Rust for Linux in CI

Rust for Linux builds as part of the suite of bors tests that run before a pull request is merged.

The workflow builds a stage1 sysroot of the Rust compiler, downloads the Linux kernel, and tries to compile several Rust for Linux drivers and examples using this sysroot. RfL uses several unstable compiler/language features, therefore this workflow notifies us if a given compiler change would break it.

If you are worried that a pull request might break the Rust for Linux builder and want to test it out before submitting it to the bors queue, simply add this line to your PR description:

try-job: x86_64-rust-for-linux

Then when you @bors try it will pick the job that builds the Rust for Linux integration.

What to do in case of failure

If a PR breaks the Rust for Linux CI job, then:

• If the breakage was unintentional and seems spurious, then let RfL know and retry.
  • If the PR is urgent and retrying doesn't fix it, then disable the CI job temporarily (comment out the image: x86_64-rust-for-linux job in src/ci/github-actions/jobs.yml).
• If the breakage was unintentional, then change the PR to resolve the breakage.
• If the breakage was intentional, then let RfL know and discuss what will the kernel need to change.
  • If the PR is urgent, then disable the CI job temporarily (comment out the image: x86_64-rust-for-linux job in src/ci/github-actions/jobs.yml).
  • If the PR can wait a few days, then wait for RfL maintainers to provide a new Linux kernel commit hash with the needed changes done, and apply it to the PR, which would confirm the changes work (update the LINUX_VERSION environment variable in src/ci/docker/scripts/rfl-build.sh).

If you need to contact the RfL developers, you can ping the Rust for Linux ping group to ask for help:

@rustbot ping rfl