GoogleContainerTools/jib · error · GradleException

Failed to generate a Jib file map for sync with Skaffold

Error message

Failed to generate a Jib file map for sync with Skaffold

What it means

After passing validation, SyncMapTask calls PluginConfigurationProcessor.getSkaffoldSyncMap to compute the sync map JSON. Any exception during that computation (or while building the Jib container context for it) is wrapped in this GradleException, so the task fails with a friendly message while retaining the cause.

Source

Thrown at jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/SyncMapTask.java:95

                  + "'");
        }
      } catch (InvalidContainerizingModeException ex) {
        throw new GradleException("Invalid containerizing mode", ex);
      }

      try {
        String syncMapJson =
            PluginConfigurationProcessor.getSkaffoldSyncMap(
                configuration,
                projectProperties,
                jibExtension.getSkaffold().getSync().getExcludes());

        System.out.println();
        System.out.println("BEGIN JIB JSON: SYNCMAP/1");
        System.out.println(syncMapJson);

      } catch (Exception ex) {
        throw new GradleException("Failed to generate a Jib file map for sync with Skaffold", ex);
      }
    }
  }
}

View on GitHub (pinned to fb949e2676)

Solutions

1. Read the 'Caused by' chain in the Gradle exception output for the root failure.
2. Run the underlying jar/build task first so expected artifacts exist before generating the sync map.
3. Fix any jib configuration (appRoot, output paths, base image) flagged by the cause.
4. Upgrade jib-gradle-plugin if the cause is a known Jib bug.

Example fix

// before: running skaffold dev without building
./gradlew jibSkaffoldSyncMap
// after
./gradlew bootJar jibSkaffoldSyncMap

// Ensure build output exists before sync-map generation
./gradlew assemble && ./gradlew jibSkaffoldSyncMap

try {
  // run sync map task
} catch (GradleException e) {
  if (e.message == 'Failed to generate a Jib file map for sync with Skaffold') {
    e.cause?.printStackTrace() // inspect root cause
  }
}

When it happens

Trigger: Running the Skaffold sync map task when getSkaffoldSyncMap throws: bad build output configuration, missing build artifacts, files not found for the build, or any internal Jib error during sync-map generation.

Common situations: Broken build outputs (e.g. jar not built or at unexpected location), misconfigured jib.build.outputPaths, or platform/registry configuration problems surfaced while computing the map.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Jib plugin version is %s but is required to be %s
• _skaffoldFailIfJibOutOfDate requires jib.requiredVersion to
• Skaffold sync is currently only available for 'jar' style Ji
• Skaffold sync is currently only available for Jib projects i
• Invalid containerizing mode

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/29f1900528bf9bed. Report an issue: GitHub.