hashicorp/terraform · error

Error chmodding script file to 0777 in remote machine

Error message

Error chmodding script file to 0777 in remote machine: %s

What it means

Returned when c.Start() fails to launch the 'chmod 0777 <path>' command that makes an uploaded script executable on a Unix target. Start wraps the SSH session exec; failure here means the command could not be initiated (session/channels problem) rather than chmod itself returning non-zero (that is the sibling 787 error). It only runs on non-Windows target_platform.

Solutions

1. Re-run apply; transient channel issues usually clear on retry.
2. Raise connection.timeout and lower parallelism if MaxSessions on the target is being hit.
3. Set script_path to a location the user can write and chmod, confirming permissions of the upload directory.
4. If persistent, check sshd config (MaxSessions, MaxStartups) and target disk/inode availability.

Example fix

// before
connection {
  host        = aws_instance.web.public_ip
  user        = "ubuntu"
  private_key = file("~/.ssh/id_rsa")
}

// after
connection {
  host        = aws_instance.web.public_ip
  user        = "ubuntu"
  private_key = file("~/.ssh/id_rsa")
  timeout     = "10m"
}

// In Go, Start failures on the chmod are often transient channel issues;
// retry a few times, then surface the wrapped error:
if strings.Contains(err.Error(), "Error chmodding script file") {
    if attempt < 3 { time.Sleep(backoff); continue }
    return fmt.Errorf("could not chmod uploaded script: %w", err)
}

When it happens

Trigger: SSH session could not be opened for exec, the channel was exhausted/closed mid-upload, or the remote shell rejected the command before execution. Network hiccup after a successful upload but before the chmod exec.

Common situations: Flaky connection that drops right after upload; sshd MaxSessions reached; the host closed the channel; very slow link causing session setup to fail.

Related errors

• Error chmodding script file to 0777 in remote machine
• Error reading script
• Error creating temporary file for upload
• Error reading error message
• Failed to upload script

AI-assisted analysis of hashicorp/terraform@d32a084675 (2026-08-11). Data as JSON: /api/errors/19814140c5aa34af. Report an issue: GitHub.

Appendix: source

Thrown at internal/communicator/ssh/communicator.go:471

	var script bytes.Buffer

	if string(prefix) != "#!" && c.connInfo.TargetPlatform != TargetPlatformWindows {
		script.WriteString(DefaultShebang)
	}
	script.ReadFrom(reader)

	if err := c.Upload(path, &script); err != nil {
		return err
	}
	if c.connInfo.TargetPlatform != TargetPlatformWindows {
		var stdout, stderr bytes.Buffer
		cmd := &remote.Cmd{
			Command: fmt.Sprintf("chmod 0777 %s", path),
			Stdout:  &stdout,
			Stderr:  &stderr,
		}
		if err := c.Start(cmd); err != nil {
			return fmt.Errorf(
				"Error chmodding script file to 0777 in remote "+
					"machine: %s", err)
		}

		if err := cmd.Wait(); err != nil {
			return fmt.Errorf(
				"Error chmodding script file to 0777 in remote "+
					"machine %v: %s %s", err, stdout.String(), stderr.String())
		}
	}
	return nil
}

// UploadDir implementation of communicator.Communicator interface
func (c *Communicator) UploadDir(dst string, src string) error {
	log.Printf("[DEBUG] Uploading dir '%s' to '%s'", src, dst)
	scpFunc := func(w io.Writer, r *bufio.Reader) error {
		uploadEntries := func() error {

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