GoogleContainerTools/jib · error · JibPluginExtensionException

extension crashed: ${ex.getMessage()}

Error message

extension crashed: ${ex.getMessage()}

What it means

The Jib plugin extension itself threw a RuntimeException while executing. MavenProjectProperties.runPluginExtension catches it and re-wraps it as a JibPluginExtensionException with the message 'extension crashed: <original message>', preserving the original as the cause.

Source

Thrown at jib-maven-plugin/src/main/java/com/google/cloud/tools/jib/maven/MavenProjectProperties.java:686

                + extraConfigType.get().getName()
                + "\">");
      } else {
        // configs is of type Optional, so this cast always succeeds
        // without the isInstance() check above. (Note generic <T> is erased at runtime.)
        extraConfig = (Optional<T>) configs;
      }
    }

    try {
      return ((JibMavenPluginExtension<T>) extension)
          .extendContainerBuildPlan(
              buildPlan,
              config.getProperties(),
              extraConfig,
              new MavenExtensionData(project, session),
              new PluginExtensionLogger(this::log));
    } catch (RuntimeException ex) {
      throw new JibPluginExtensionException(
          extension.getClass(), "extension crashed: " + ex.getMessage(), ex);
    }
  }

  private JibMavenPluginExtension<?> findConfiguredExtension(
      List<JibMavenPluginExtension<?>> extensions, ExtensionConfiguration config)
      throws JibPluginExtensionException {
    Predicate<JibMavenPluginExtension<?>> matchesClassName =
        extension -> extension.getClass().getName().equals(config.getExtensionClass());
    Optional<JibMavenPluginExtension<?>> found =
        extensions.stream().filter(matchesClassName).findFirst();
    if (!found.isPresent()) {
      throw new JibPluginExtensionException(
          NullExtension.class,
          "extension configured but not discovered on Jib runtime classpath: "
              + config.getExtensionClass());
    }
    return found.get();

View on GitHub (pinned to fb949e2676)

Solutions

1. Read the caused-by stack trace below 'extension crashed' to find the real exception thrown inside the extension.
2. Upgrade (or align) the extension and jib-maven-plugin versions — crashes often stem from version incompatibilities.
3. Fix the extension's inputs: missing configuration values, absent files, or project layout assumptions that triggered the NPE/error.
4. If it's a third-party extension bug, reproduce minimally and report it upstream with the full stack trace.

// Smoke-test the extension in isolation before wiring it into the build:
// call extendContainerBuildPlan with a minimal plan in a unit test to surface NPEs early.

try {
  // mvn jib:build with extensions
} catch (JibPluginExtensionException e) {
  if (e.getMessage().startsWith("extension crashed:")) {
    e.getCause().printStackTrace(); // inspect the real RuntimeException inside the extension
  }
  throw e;
}

When it happens

Trigger: Any unchecked exception inside the extension's extendContainerBuildPlan or applyContainerBuildPlan: NPEs from missing config values, ClassNotFound/NoClassDefFound from classpath conflicts, illegal argument states in extension logic, or failures reading project resources.

Common situations: Third-party extensions (e.g. jib-spring-boot) hitting unexpected project layouts; extension code assuming files/classes that don't exist in this project; extension version incompatibility with the Jib core version on the plugin classpath.

Related errors

• extension crashed: ${ex.getMessage()}
• error running extension '${extensionName}': ${ex.getMessage(
• invalid base image reference: ${buildPlan.getBaseImage()}
• extension ${extension.getClass().getSimpleName()} does not e
• error running extension '<extensionClassName>': <message>

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/6be07e59ab17b860. Report an issue: GitHub.