Build Tool Wrapper Exists
java.build-tool-wrapper-exists
Ensures a build tool wrapper exists (mvnw for Maven projects, gradlew for Gradle projects). Wrappers ensure reproducible builds without requiring a pre-installed build tool.
Compatible Integrations
This guardrail works with the following integrations. Click to see how to use Build Tool Wrapper Exists with each collector.
Enable This Guardrail
Add the parent policy to your lunar-config.yml to enable this guardrail.
policies:
- uses: github://earthly/lunar-lib/policies/java@v1.0.0
include: [build-tool-wrapper-exists]
# with: ...How This Guardrail Works
This guardrail is part of the Java Project Guardrails policy. It evaluates data collected by integrations and produces a pass/fail check with actionable feedback.
When enabled, this check runs automatically on every PR and in AI coding workflows, providing real-time enforcement of your engineering standards.
Learn How Lunar Works →Configuration Options
These inputs can be configured in your lunar-config.yml to customize
how the parent policy (and this guardrail) behaves.
| Input | Required | Default | Description |
|---|---|---|---|
min_java_version
|
Optional |
17
|
Minimum required Java version (e.g., "17", "21") |
min_maven_version
|
Optional |
3.9.0
|
Minimum required Maven version (e.g., "3.9.0") |
min_gradle_version
|
Optional |
8.0.0
|
Minimum required Gradle version (e.g., "8.0.0") |
Java Project Guardrails
This guardrail is part of the Java Project Guardrails policy, which includes 5 guardrails for devex build and ci.
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