What causes "%s is missing from build configuration; ignoring auth section." in GoogleContainerTools/jib?

Add the missing username to the auth block in the build configuration

%s is missing from build configuration; ignoring auth sectio

Error message

%s is missing from build configuration; ignoring auth section.

What it means

ConfigurationPropertyValidator.getImageCredential logs this warning when the build configuration's auth section has a password but no username (the message reports the missing username via auth.getUsernameDescriptor()). The incomplete auth entry is ignored and Jib falls back to other credential sources.

Source

Thrown at jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/ConfigurationPropertyValidator.java:85

    String missingProperty =
        "%s system property is set, but %s is not; attempting other authentication methods.";
    if (!commandlinePassword.isEmpty()) {
      logger.accept(
          LogEvent.warn(String.format(missingProperty, passwordProperty, usernameProperty)));
    }
    if (!commandlineUsername.isEmpty()) {
      logger.accept(
          LogEvent.warn(String.format(missingProperty, usernameProperty, passwordProperty)));
    }

    // Check auth configuration next; warn if they aren't both set
    if (!Strings.isNullOrEmpty(auth.getUsername()) && !Strings.isNullOrEmpty(auth.getPassword())) {
      return Optional.of(Credential.from(auth.getUsername(), auth.getPassword()));
    }

    String missingConfig = "%s is missing from build configuration; ignoring auth section.";
    if (!Strings.isNullOrEmpty(auth.getPassword())) {
      logger.accept(LogEvent.warn(String.format(missingConfig, auth.getUsernameDescriptor())));
    }
    if (!Strings.isNullOrEmpty(auth.getUsername())) {
      logger.accept(LogEvent.warn(String.format(missingConfig, auth.getPasswordDescriptor())));
    }

    return Optional.empty();
  }

  /**
   * Returns an {@link ImageReference} parsed from the configured target image, or one of the form
   * {@code project-name:project-version} if target image is not configured.
   *
   * @param targetImage the configured target image reference
   * @param projectProperties the {@link ProjectProperties} providing the project name, version, and
   *     log event handler
   * @param helpfulSuggestions used for generating the message notifying the user of the generated
   *     tag
   * @return an {@link ImageReference} parsed from the configured target image, or one of the form

View on GitHub (pinned to fb949e2676)

Solutions

Add the missing username to the auth block in the build configuration
Check that any variable used for the username resolves to a non-empty value in the build environment
Remove the auth block entirely if you intend to use system properties or a credential helper
Validate the full credential pair before the build (fail fast with a pre-build check)

Example fix

// before: build.gradle
jib { to { auth { password = 'secret' } } }
// after
jib { to { auth { username = 'user'; password = 'secret' } } }

Defensive patterns

Strategy: validation

Validate before calling

// gradle pre-flight: auth must be a complete pair
afterEvaluate {
  def auth = jib.to.auth
  if ((auth.password && !auth.username) || (auth.username && !auth.password))
    throw new GradleException("jib.to.auth requires both username and password")
}

Try / catch

def credential = null
if (auth?.username && auth?.password) credential = Credential.from(auth.username, auth.password)
// otherwise skip auth entirely instead of a partial config

Prevention

Keep auth username/password together in one config block
Avoid interpolated variables in auth fields that may resolve to empty strings
Centralize registry credentials in one reviewed location

When it happens

Trigger: build.gradle/pom.xml contains to.auth.password (non-empty) while to.auth.username is null/empty; the check at line 85 fires inside getImageCredential before returning Optional.empty().

Common situations: Editing build files and forgetting one auth field; templated configs where a variable (e.g. ${REGISTRY_USER}) resolves to empty; migrating configs and dropping one line.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/e4f966aa77d8de74. Report an issue: GitHub.