GoogleContainerTools/jib · error · GradleException

container.appRoot is not an absolute Unix-style path: ${inva

Error message

container.appRoot is not an absolute Unix-style path: ${invalidPathValue}

What it means

Thrown by Jib's Gradle plugin when the container.appRoot configuration value is not an absolute Unix-style path (e.g. must start with '/'). Jib needs a valid absolute target directory on the container filesystem where the app files are placed. It wraps InvalidAppRootException into a GradleException so the build fails with a clear message including the offending value.

Source

Thrown at jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildDockerTask.java:129

            getProject(),
            getLogger(),
            tempDirectoryProvider,
            jibExtension.getConfigurationName().get());
    GlobalConfig globalConfig = GlobalConfig.readConfig();
    Future<Optional<String>> updateCheckFuture =
        TaskCommon.newUpdateChecker(projectProperties, globalConfig, getLogger());
    try {

      PluginConfigurationProcessor.createJibBuildRunnerForDockerDaemonImage(
              new GradleRawConfiguration(jibExtension),
              ignored -> java.util.Optional.empty(),
              projectProperties,
              globalConfig,
              new GradleHelpfulSuggestions(HELPFUL_SUGGESTIONS_PREFIX))
          .runBuild();

    } catch (InvalidAppRootException ex) {
      throw new GradleException(
          "container.appRoot is not an absolute Unix-style path: " + ex.getInvalidPathValue(), ex);

    } catch (InvalidContainerizingModeException ex) {
      throw new GradleException(
          "invalid value for containerizingMode: " + ex.getInvalidContainerizingMode(), ex);

    } catch (InvalidWorkingDirectoryException ex) {
      throw new GradleException(
          "container.workingDirectory is not an absolute Unix-style path: "
              + ex.getInvalidPathValue(),
          ex);

    } catch (InvalidPlatformException ex) {
      throw new GradleException(
          "from.platforms contains a platform configuration that is missing required values or has invalid values: "
              + ex.getMessage()
              + ": "
              + ex.getInvalidPlatform(),

View on GitHub (pinned to fb949e2676)

Solutions

  1. Prefix appRoot with a forward slash so it is absolute Unix-style, e.g. appRoot = "/app"
  2. Remove any Windows drive letters or backslashes; use forward slashes only
  3. If targeting a Windows container, note Jib requires Unix-style absolute paths for appRoot

Example fix

// before
jib { container { appRoot = 'myapp' } }
// after
jib { container { appRoot = '/myapp' } }
Defensive patterns

Strategy: validation

Validate before calling

def appRoot = jib.container.appRoot
if (appRoot != null && !appRoot.startsWith('/')) {
  throw new GradleException("appRoot must be absolute Unix path, got: $appRoot")
}

Try / catch

try { jibBuild.run() } catch (GradleException e) { if (e.message.contains('container.appRoot')) { logger.error("Fix appRoot to an absolute path: " + e.message) ; throw e } throw e }

Prevention

When it happens

Trigger: Setting appRoot in the jib { container { appRoot = ... } } block to a relative path like 'app' or 'my/app', a Windows-style path like 'C:\app', or a path with a drive letter/leading non-slash character.

Common situations: Migrating configs from Windows dev machines, copying appRoot settings from Docker/other tools that use relative paths, or typo-ing the leading slash when configuring a custom deployment directory (e.g. /deploy/myapp).

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/e24b1949cf47382c. Report an issue: GitHub.