apache/beam · error

source path doesn't exist

Error message

source path %s doesn't exist: %w

What it means

packJar failed at os.Stat(source): the directory or file being repacked into the JAR does not exist (or is inaccessible). This happens after the destination jar was already created, so a partial/empty jar file may be left on disk. The underlying os.Stat error is wrapped with the source path.

Solutions

1. Verify the source path exists with ls before packing; recreate it (re-run extractJar on the main JAR).
2. Remove stale tmpDir under the jar cache and retry so extraction recreates it.
3. Avoid concurrent processes sharing the same jar cache directory.
4. If calling packJar directly, validate os.Stat(source) yourself first and fail early.

Example fix

// before
packJar(tmpDir, outJar)
// after
if _, err := os.Stat(tmpDir); err != nil {
    return fmt.Errorf("source %s missing: %w", tmpDir, err)
}
packJar(tmpDir, outJar)

if _, err := os.Stat(source); err != nil {
    return fmt.Errorf("source %s unavailable: %w", source, err)
}

if err := packJar(source, dest); err != nil {
    if errors.Is(err, fs.ErrNotExist) {
        // recreate source tree (re-run extractJar) and retry once
    }
    return err
}

When it happens

Trigger: packJar(source, dest) is called with a source path that was deleted, never created, or is unreadable — e.g. the tmpDir produced by extractJar was removed, or MakeJar was pointed at a mainJar that failed to extract fully.

Common situations: Stale or concurrently deleted ~/.beam661bea09-.../tmpDir; another process cleaned the cache mid-run; typo'd path passed to a custom caller of packJar; extractJar failed silently earlier leaving no tmpDir.

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

• error in creating relative path
• error creating jar packJar
• error opening destination file
• error opening file
• can't change to old working directory

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/e47c8e270dcf8a42. Report an issue: GitHub.

Appendix: source

Thrown at sdks/go/pkg/beam/core/runtime/xlangx/expansionx/download.go:205

			return err
		}
	}
	return nil
}

func packJar(source, dest string) error {
	jar, err := os.Create(dest)
	if err != nil {
		return fmt.Errorf("error creating jar packJar(%s,%s)=%w", source, dest, err)
	}
	defer jar.Close()

	jarFile := zip.NewWriter(jar)
	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))

View on GitHub (pinned to 12126d8942)