update

The update command generates and updates BUILD files by running Gazelle with all enabled language extensions.

Usage

bazelle update [flags] [path...]

Flags

Flag	Description
--check	Check if BUILD files are up to date (exit 1 if changes needed)
--incremental	Only update directories with changed source files
--force	Force full update, ignoring cached state
--languages	Only run specific language extensions (comma-separated)
--verbose	Show detailed output

Examples

Basic Update

Update all BUILD files in the current workspace:

bazelle update

Update a specific directory:

bazelle update ./src/mypackage

CI Integration

Check if BUILD files are up to date without modifying them:

bazelle update --check

Tip

Use --check in CI pipelines to ensure BUILD files are committed and up to date.

Example CI output:

BUILD files need updating (3 file(s) would change)
Run 'bazelle update' to apply changes

Incremental Mode

For large codebases, incremental mode only updates directories with changed files:

bazelle update --incremental

How it works:

1. On first run, Bazelle scans all source files and stores their hashes
2. On subsequent runs, only directories with changed files are updated
3. State is stored in .bazelle/ in your workspace root

# First run - full update, stores state
bazelle update --incremental

# Subsequent runs - only changed directories
bazelle update --incremental

# Force full update despite incremental flag
bazelle update --incremental --force

Language Filtering

Run only specific language extensions:

# Only Go and Kotlin
bazelle update --languages go,kotlin

# Only Python
bazelle update --languages python

Verbose Output

Show detailed information:

bazelle update --verbose

Example verbose output:

Languages: go, kotlin, python, cc
Processing 847 files in 123 packages...
Updated: src/auth/BUILD.bazel
Updated: src/api/BUILD.bazel
Unchanged: 121 packages
State saved (847 files tracked)

Passthrough Flags

Flags not recognized by Bazelle are passed to Gazelle:

# Set Go prefix (passed to gazelle)
bazelle update -go_prefix=github.com/org/repo

# Use bzlmod mode
bazelle update -bzlmod

# Specify build tags
bazelle update -build_tags=integration

Exit Codes

Code	Mode	Meaning
0	Normal	Update completed successfully
0	--check	BUILD files are up to date
1	--check	BUILD files need updating
1	Any	Error occurred

Comparison with fix

Command	Changes	Use Case
update	Additive only	Regular development
fix	May delete/rename rules	Major refactoring

Use update for day-to-day development. Use fix when you’ve renamed or deleted source files and need to clean up obsolete BUILD rules.