hyperledger/fabric · error

failed to write %s as %s: %s

Error message

failed to write %s as %s: %s

What it means

The final step copies file contents into the tar stream with io.Copy(tw, is). This error means reading localpath or writing to the tar stream failed mid-copy, producing a truncated/corrupt package. Message format: local path, package path, underlying error.

Source

Thrown at core/chaincode/platforms/util/writer.go:145

	header.AccessTime = zeroTime
	header.ModTime = zeroTime
	header.ChangeTime = zeroTime
	header.Name = packagepath
	header.Mode = 0o100644
	header.Uid = 500
	header.Gid = 500
	header.Uname = ""
	header.Gname = ""

	err = tw.WriteHeader(header)
	if err != nil {
		return fmt.Errorf("failed to write header for %s: %s", localpath, err)
	}

	is := bufio.NewReader(fd)
	_, err = io.Copy(tw, is)
	if err != nil {
		return fmt.Errorf("failed to write %s as %s: %s", localpath, packagepath, err)
	}

	return nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Check the wrapped error for ENOSPC/disk-full and free space on the package destination
2. Re-run packaging after ensuring the source tree is quiescent (no concurrent builds/deletes)
3. If sources are on NFS, copy to local disk first, then package; validate the resulting tar (tar -tf) before use

Example fix

// before
goutil.WriteFileToPackage(srcOnNfs, pkgPath, tw) // truncated package on NFS hiccup
// after
localCopy := filepath.Join(os.TempDir(), filepath.Base(srcOnNfs))
copyFile(srcOnNfs, localCopy) // snapshot to stable local disk
err := util.WriteFileToPackage(localCopy, pkgPath, tw)
// then verify: tar -tf pkgPath

// pre-check source readability and destination free space
if fi, err := os.Stat(localpath); err != nil || !fi.Mode().IsRegular() {
    return fmt.Errorf("bad package input %s", localpath)
}
if err := checkDiskSpace(filepath.Dir(pkgPath), 256<<20); err != nil { return err }

func isReadableRegular(path string) bool {
    f, err := os.Open(path)
    if err != nil { return false }
    f.Close()
    return true
}

if err := util.WriteFileToPackage(localpath, pkgPath, tw); err != nil {
    if strings.Contains(err.Error(), "failed to write") {
        os.Remove(pkgPath) // discard truncated package
        return fmt.Errorf("package %s incomplete (source %s): %w", pkgPath, localpath, err)
    }
    return err
}

When it happens

Trigger: io.Copy fails: file shrank or read error while streaming (file modified/truncated concurrently), writer-side failure (disk full, network stream broken), or fd closed early.

Common situations: Disk full on the volume holding the chaincode package; source file being rebuilt while packaging; network file system dropping the connection mid-read.

Related errors

• failed to write header for %s: %s
• failed calculating FileInfoHeader: %s
• Recv() error: %v, closing connection
• chaincode stream terminated
• illegal file name in payload: %s

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/21155ae44e872e90. Report an issue: GitHub.