What causes "Cannot create FileLayers from non-file, non-directory: ${src}" in GoogleContainerTools/jib?

Verify the src path exists relative to the build root (or make it absolute).

GoogleContainerTools/jib · error · UnsupportedOperationException

Cannot create FileLayers from non-file, non-directory: ${src

Error message

Cannot create FileLayers from non-file, non-directory: ${src}

What it means

When converting FileLayerSpec copy directives into layer entries, Layers.toLayers resolves each src (relative to buildRoot) and requires it to be either a directory or a regular file. If Files.isDirectory and Files.isRegularFile both fail (missing path, broken symlink, special file), it throws UnsupportedOperationException naming the src.

Source

Thrown at jib-cli/src/main/java/com/google/cloud/tools/jib/cli/buildfile/Layers.java:82

      // each loop is a new layer
      if (entry instanceof FileLayerSpec) {
        FileEntriesLayer.Builder layerBuiler = FileEntriesLayer.builder();

        FileLayerSpec fileLayer = (FileLayerSpec) entry;
        layerBuiler.setName(fileLayer.getName());
        // layer properties
        fileLayer.getProperties().ifPresent(filePropertiesStack::push);
        for (CopySpec copySpec : ((FileLayerSpec) entry).getFiles()) {
          // copy spec properties
          copySpec.getProperties().ifPresent(filePropertiesStack::push);

          // relativize all paths to the buildRoot location
          Path rawSrc = copySpec.getSrc();
          Path src = rawSrc.isAbsolute() ? rawSrc : buildRoot.resolve(rawSrc);
          AbsoluteUnixPath dest = copySpec.getDest();

          if (!Files.isDirectory(src) && !Files.isRegularFile(src)) {
            throw new UnsupportedOperationException(
                "Cannot create FileLayers from non-file, non-directory: " + src.toString());
          }
          if (Files.isRegularFile(src)) { // regular file
            if (!copySpec.getExcludes().isEmpty() || !copySpec.getIncludes().isEmpty()) {
              throw new UnsupportedOperationException(
                  "Cannot apply includes/excludes on single file copy directives.");
            }
            layerBuiler.addEntry(
                src,
                copySpec.isDestEndsWithSlash() ? dest.resolve(src.getFileName()) : dest,
                filePropertiesStack.getFilePermissions(),
                filePropertiesStack.getModificationTime(),
                filePropertiesStack.getOwnership());
          } else if (Files.isDirectory(src)) { // directory
            List<PathMatcher> excludes =
                copySpec.getExcludes().stream()
                    .map(Layers::toPathMatcher)
                    .collect(Collectors.toList());

View on GitHub (pinned to fb949e2676)

Solutions

Verify the src path exists relative to the build root (or make it absolute).
Run the build step that produces the file/directory before Jib.
Fix or remove dangling symlinks in the copied tree.
Check that the build root (-Djib.alwaysCacheWorkDir / build context dir) is the directory you expect.

Example fix

// before
{"name": "app", "files": [{"src": "target/app.jar", "dest": "/app"}]} // jar not built
// after
mvn package && jib ...  // ensure target/app.jar exists first

Defensive patterns

Strategy: validation

Validate before calling

Path src = buildRoot.resolve(copySpec.getSrc());
if (!Files.isDirectory(src) && !Files.isRegularFile(src)) {
  throw new IllegalStateException("Copy src does not exist: " + src);
}

Try / catch

try {
  jibBuild();
} catch (UnsupportedOperationException e) {
  if (e.getMessage().startsWith("Cannot create FileLayers from non-file, non-directory")) {
    log.error("Check src paths in build file relative to build root: {}", e.getMessage());
  } else throw e;
}

Prevention

Verify all copy src paths exist before running Jib
Run artifact-producing build steps first
Run Jib from the expected working directory
Clean dangling symlinks from the source tree

When it happens

Trigger: A copy spec's src path does not exist relative to the build root, points to a broken symlink, or is a special file (socket, device, fifo).

Common situations: Typos in src paths, running the CLI from the wrong working directory so relative srcs don't resolve, artifacts not yet built, dangling symlinks in the source tree.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of GoogleContainerTools/jib@fb949e2676 (2026-09-06). Data as JSON: /api/errors/fae28a4b488c6021. Report an issue: GitHub.