apache/beam · warning

error getting FileInfoHeader

Error message

error getting FileInfoHeader: %w

What it means

zip.FileInfoHeader(fileInfo) returned an error while converting an os.FileInfo from the walk into a zip header. This is rare in practice — it only fails when the FileInfo's Sys() cannot be converted to the OS-specific type, so it usually indicates an unusual filesystem or a FileInfo not backed by a real OS file.

Solutions

1. Retry on a standard local filesystem (move the source tree off the FUSE/network mount).
2. Verify you are passing real os.Stat-derived FileInfo values, not synthetic ones.
3. Update Go version if a platform-specific zip.FileInfoHeader bug is suspected; check the release notes.
4. As a workaround, construct zip.FileHeader manually (SetModTime/SetMode) from name+mode instead of FileInfoHeader.

fileHeader, err := zip.FileInfoHeader(fileInfo)
if err != nil {
    // fall back to a manual header instead of failing the whole pack
    fileHeader = &zip.FileHeader{Name: filepath.Base(path)}
    fileHeader.SetMode(fileInfo.Mode())
}

When it happens

Trigger: During packJar's filepath.Walk, zip.FileInfoHeader receives a FileInfo whose underlying system data is nil or of unexpected type (not *syscall.Stat_t on Linux), e.g. from synthetic FileInfos or exotic FUSE/overlay filesystems.

Common situations: Packing a tree on an unusual mounted filesystem (some FUSE mounts, network filesystems) where Sys() is not the expected type; calling packJar with mocked FileInfos in tests.

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

• error copying file
• error creating jarFile header
• error in extractJar()
• error in packJar()
• error opening jar for extractJar

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/319837a32a44220e. Report an issue: GitHub.

Appendix: source

Thrown at sdks/go/pkg/beam/core/runtime/xlangx/expansionx/download.go:219

	defer jarFile.Close()

	fileInfo, err := os.Stat(source)
	if err != nil {
		return fmt.Errorf("source path %s doesn't exist: %w", source, err)
	}

	var sourceDir string
	if fileInfo.IsDir() {
		sourceDir = filepath.Base(source)
	}

	err = filepath.Walk(source, func(path string, fileInfo os.FileInfo, err error) error {
		if err != nil {
			return fmt.Errorf("error accesing path %s: %w", path, err)
		}
		fileHeader, err := zip.FileInfoHeader(fileInfo)
		if err != nil {
			return fmt.Errorf("error getting FileInfoHeader: %w", err)
		}

		if sourceDir != "" {
			fileHeader.Name = filepath.Join(sourceDir, strings.TrimPrefix(path, source))
		}

		if fileInfo.IsDir() {
			fileHeader.Name += "/"
		} else {
			fileHeader.Method = zip.Deflate
		}

		writer, err := jarFile.CreateHeader(fileHeader)
		if err != nil {
			return fmt.Errorf("error creating jarFile header: %w", err)
		}
		if fileInfo.IsDir() {
			return nil

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