GoogleContainerTools/jib · error · IOException

Obtaining project build output files failed; make sure you h

Error message

Obtaining project build output files failed; make sure you have ${packaged|compiled} your project before trying to build the image. (Did you accidentally run "mvn clean jib:build" instead of "mvn clean ${package|compile} jib:build"?)

What it means

Jib could not find any project build output files (jars/classes) to layer into the image because the project was compiled with 'clean' but never packaged or compiled. Maven goals like 'jib:build' do not themselves trigger the lifecycle phases that produce artifacts, so Jib has nothing to containerize and throws this IOException from MavenProjectProperties.createJibContainerBuilder.

Source

Thrown at jib-maven-plugin/src/main/java/com/google/cloud/tools/jib/maven/MavenProjectProperties.java:318

        default:
          throw new IllegalStateException("unknown containerizing mode: " + containerizingMode);
      }

      // Classify and add dependencies
      Map<LayerType, List<Path>> classifiedDependencies =
          classifyDependencies(project.getArtifacts(), getProjectDependencies());

      javaContainerBuilder.addDependencies(
          Preconditions.checkNotNull(classifiedDependencies.get(LayerType.DEPENDENCIES)));
      javaContainerBuilder.addSnapshotDependencies(
          Preconditions.checkNotNull(classifiedDependencies.get(LayerType.SNAPSHOT_DEPENDENCIES)));
      javaContainerBuilder.addProjectDependencies(
          Preconditions.checkNotNull(classifiedDependencies.get(LayerType.PROJECT_DEPENDENCIES)));
      return javaContainerBuilder.toContainerBuilder();

    } catch (IOException ex) {
      throw new IOException(
          "Obtaining project build output files failed; make sure you have "
              + (isPackageErrorMessage(containerizingMode) ? "packaged" : "compiled")
              + " your project "
              + "before trying to build the image. (Did you accidentally run \"mvn clean "
              + "jib:build\" instead of \"mvn clean "
              + (isPackageErrorMessage(containerizingMode) ? "package" : "compile")
              + " jib:build\"?)",
          ex);
    }
  }

  @VisibleForTesting
  Set<Artifact> getProjectDependencies() {
    return session.getProjects().stream()
        .map(MavenProject::getArtifact)
        .filter(artifact -> !artifact.equals(project.getArtifact()))
        .filter(artifact -> artifact.getFile() != null)
        .collect(Collectors.toSet());

View on GitHub (pinned to fb949e2676)

Solutions

Run the full lifecycle before Jib: 'mvn clean package jib:build' (or 'mvn clean compile jib:build' if using containerizingMode=exploded).
Verify your containerizingMode setting (<containerizingMode> in pom.xml) matches the phase you ran — packaged requires package, exploded requires compile.
Check CI pipelines and wrapper scripts for the accidental 'mvn clean jib:build' pattern and add the missing phase.
Bind jib to the package phase via an <execution> so the artifact always exists when it runs.

Example fix

// before
mvn clean jib:build

// after
mvn clean package jib:build

Defensive patterns

Strategy: validation

Validate before calling

// Check target output exists before invoking jib goals
if (!java.nio.file.Files.exists(java.nio.file.Path.of("target", "classes"))
    && !java.nio.file.Files.exists(java.nio.file.Path.of("target", "*.jar"))) {
  throw new IllegalStateException("Run 'mvn package' (or 'compile' for exploded mode) before jib:build");
}

Try / catch

try {
  // mvn clean package jib:build
} catch (IOException e) {
  if (e.getMessage().contains("Obtaining project build output files failed")) {
    // rerun with package phase: mvn clean package jib:build
  }
  throw e;
}

Prevention

Always pair jib goals with a producing phase: 'mvn clean package jib:build'.
Bind the jib goal to the package phase in pom.xml executions so it never runs standalone.
Match containerizingMode (packaged vs exploded) to the phase you run.
Keep CI scripts reviewed so 'jib:build' never directly follows 'clean'.

When it happens

Trigger: Running 'mvn clean jib:build' or 'mvn clean jib:dockerBuild' without a preceding 'package' (or 'compile' when containerizingMode=packaged... actually processed) phase; running jib goals directly on a freshly cleaned workspace; building from an IDE goal that skips lifecycle phases.

Common situations: Developer assumes the jib plugin goal runs the package phase automatically; CI scripts calling 'mvn clean jib:build'; switching containerizingMode between 'packaged' and 'exploded' so the required phase changes; typo in a wrapper script omitting 'package'.

Understand the failure class

Background: "X is required", "must be set", "cannot be empty": the missing-required-config error family, from Vertex AI project/location to WeChat keys — this error's family across 18 libraries.

Related errors

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/b28951d5792ae06c. Report an issue: GitHub.