prek

name	Prek
description	Instructions for running prek, the Carbon pre-submit/style/lint checker, that *MUST* be run before submitting an change.

Prek

prek is the Carbon pre-submit, style, and lint checker. Running it is mandatory before submitting any changes.

Running prek

To run prek on all files:

prek run -a

To validate a specific list of files:

prek run --files <files>

Running prek in a Jujutsu (jj) workspace

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.

Prek dependency errors

[!TIP] If prek fails with an error about resolving dependencies or security policy, you may be running in a restricted environment where the special-purpose gpkg tool is required. Prefix the command with gpkg, for example: gpkg prek run -a or gpkg ./scripts/jj_prek.sh.