Menu
Instructions for running prek, the Carbon pre-submit/style/lint checker, that *MUST* be run before submitting an change.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Based on SOC occupation classification
Instructions for registering, mapping, constant evaluating, and lowering builtin functions in the Carbon toolchain.
Instructions for declaring, formatting, emitting, testing, and styling diagnostic messages (errors, warnings, notes) in the Carbon toolchain.
Guidelines and restrictions on shell commands and file manipulation tools for AI assistants.
Instructions that **MUST** be followed when using Bazel or Bazelisk to build, test, and debug in the Carbon repository.
Instructions for using Jujutsu (jj) for version control in the Carbon repository.
Instructions for authoring, structuring, and running toolchain tests using the file_test infrastructure.
| name | Prek |
| description | Instructions for running prek, the Carbon pre-submit/style/lint checker, that *MUST* be run before submitting an change. |
prek is the Carbon pre-submit, style, and lint checker. Running it is
mandatory before submitting any changes.
To run prek on all files:
prek run -a
To validate a specific list of files:
prek run --files <files>
If you are working in a Jujutsu workspace, running prek directly will fail
because it expects a standard Git repository structure. Instead, use the helper
script:
./scripts/jj_prek.sh
This script runs prek on all files that have changed between trunk and your
current Jujutsu @ change.
[!TIP] If
prekfails with an error about resolving dependencies or security policy, you may be running in a restricted environment where the special-purposegpkgtool is required. Prefix the command withgpkg, for example:gpkg prek run -aorgpkg ./scripts/jj_prek.sh.