hashicorp/terraform · error

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

Error message

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

What it means

Raised in Communicator.UploadScript when c.Start(cmd) fails for the remote 'chmod 0777 <path>' command that runs after a successful script upload on unix targets. Start opens a new SSH session and begins the command; a failure here means the session could not be established or the command could not be launched (e.g. connection dropped, session allocation failed, or PTY request failed).

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 {

View on GitHub (pinned to c9def3e214)

Solutions

1. Check that the SSH connection is stable and not timing out between upload and chmod (increase connection timeout in the provisioner connection block).
2. Verify the remote sshd MaxSessions and MaxStartups limits are not exhausted.
3. Ensure the script_path does not contain characters that break the remote shell.
4. Retry the provisioner run; transient connection drops during long uploads are common.

Example fix

// before
connection {
  host     = var.host
  timeout  = "30s"
}

// after
connection {
  host     = var.host
  timeout  = "10m"
}

// Wrap UploadScript with retry on session-start failure
func uploadScriptWithRetry(comm *Communicator, path string, r io.Reader, maxRetries int) error {
    for i := 0; i < maxRetries; i++ {
        err := comm.UploadScript(path, r)
        if err == nil {
            return nil
        }
        if strings.Contains(err.Error(), "chmodding script file to 0777") {
            time.Sleep(time.Duration(i+1) * 2 * time.Second)
            continue
        }
        return err
    }
    return errors.New("max retries exceeded for script upload")
}

When it happens

Trigger: After the script file is uploaded via SCP, the communicator starts a remote chmod command. This error fires if newSession() fails (client disconnected or nil), if session.RequestPty() fails, or if session.Start() returns an error for the chmod invocation.

Common situations: The SSH connection dropped between the SCP upload and the chmod call (e.g. server-side idle timeout, network blip), the remote sshd has a low MaxSessions limit and the session cannot be allocated, or the script path contains characters that break the remote shell.

Related errors

• Error reading script: %s
• Error chmodding script file to 0777 in remote machine %v: %s
• Upload failed: %v
• Failed to upload script: %v
• Error starting script: %v

AI-assisted analysis of hashicorp/terraform@c9def3e214 (2026-08-07). Data as JSON: /api/errors/19814140c5aa34af. Report an issue: GitHub.