kovidgoyal/kitty · error

failed to upload %s: %w

Error message

failed to upload %s: %w

What it means

In the remote_file edit loop, once the local editor signals done, the file is re-uploaded over the SSH ControlMaster. This error means Upload() returned an error (the underlying scp/ssh copy failed) while the master process was still alive; the remote path is included.

Source

Thrown at kittens/remote_file/actions.go:188

	// Mirrors main.py handle_action's edit branch: reset the terminal (clear
	// whatever the ask-menu/hostname-prompt phases drew) right before handing
	// the screen to the user's $EDITOR, and again once it exits.
	reset_terminal()
	argv := append(append([]string{}, editor...), master.Dest)
	cmd := exec.Command(argv[0], argv[1:]...)
	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	if err := cmd.Start(); err != nil {
		return err
	}
	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()
	for {
		select {
		case <-done:
			reset_terminal()
			if master.IsAlive() {
				if err := master.Upload(false); err != nil {
					return fmt.Errorf("failed to upload %s: %w", master.remote_path, err)
				}
				return nil
			}
			return fmt.Errorf("failed to upload %s, SSH master process died", master.remote_path)
		case <-time.After(100 * time.Millisecond):
			if st, err := os.Stat(master.Dest); err == nil && st.ModTime().After(mtime) {
				mtime = st.ModTime()
				if master.IsAlive() {
					_ = master.Upload(true)
				}
			}
		}
	}
}

View on GitHub (pinned to 6d5d0c4406)

Solutions

1. Check the wrapped error for the underlying scp/ssh failure reason
2. Verify the remote path still exists and is writable
3. Retry the edit/upload; if persistent, re-establish the ControlMaster
4. Ensure remote disk space and permissions are adequate

if err := handle_action(...); err != nil && strings.Contains(err.Error(), "failed to upload") {
    // re-check remote writability, re-establish master, retry upload
}

When it happens

Trigger: Calling handle_action for an edit where the remote host rejects the copy (permissions changed, disk full, remote path removed) even though the ssh master is up.

Common situations: Remote file deleted or permissions changed while editing, remote filesystem full, or transient network degradation causing the multiplexed copy to fail.

Related errors

• failed to upload %s, SSH master process died
• This should be run as kitten ssh
• Incorrect owner on pwfile: uid={shm.stats.st_uid} gid={shm.s
• Incorrect permissions on pwfile: 0o{mode:03o}
• Incorrect password

AI-assisted analysis of kovidgoyal/kitty@6d5d0c4406 (2026-08-27). Data as JSON: /api/errors/ddded174a8ffedae. Report an issue: GitHub.