tui-cs/Terminal.Gui · warning · TimeoutException

Process timed out. Command line: {process.StartInfo.FileName

Error message

Process timed out. Command line: {process.StartInfo.FileName} {process.StartInfo.Arguments}.

What it means

Thrown as TimeoutException by ClipboardProcessRunner.Process when the spawned helper process (bash/xclip/xsel/etc.) does not exit within 5000ms. The message includes the command line for diagnosis. This protects the UI thread from hanging indefinitely on an unresponsive clipboard helper.

Source

Thrown at Terminal.Gui/App/Clipboard/ClipboardProcessRunner.cs:65

            RedirectStandardInput = true,
            UseShellExecute = false,
            CreateNoWindow = true
        };

        process.Start ();

        if (!string.IsNullOrEmpty (input))
        {
            process.StandardInput.Write (input);
            process.StandardInput.Close ();
        }

        if (!process.WaitForExit (5000))
        {
            var timeoutError =
                $@"Process timed out. Command line: {process.StartInfo.FileName} {process.StartInfo.Arguments}.";

            throw new TimeoutException (timeoutError);
        }

        if (waitForOutput && process.StandardOutput.Peek () != -1)
        {
            output = process.StandardOutput.ReadToEnd ();
        }

        if (process.ExitCode > 0)
        {
            output = $@"Process failed to run. Command line: {cmd} {arguments}.
										Output: {output}
										Error: {process.StandardError.ReadToEnd ()}";
        }

        return (process.ExitCode, output);
    }
}

View on GitHub (pinned to 2e47b11478)

Solutions

Switch to a clipboard helper that daemonizes the selection, or use xclip with options that avoid holding the selection open.
Ensure a healthy clipboard daemon / display server is running in the session.
Catch TimeoutException and fall back to an in-memory clipboard or disable OS clipboard sync.
Prefer the Try* clipboard methods which do not throw on failure.

Example fix

// before
string text = Application.Driver.Clipboard.GetClipboardData (); // helper hangs -> TimeoutException

// after
if (Application.Driver.Clipboard.TryGetClipboardData (out string text))
{
    // use text
}
else
{
    // clipboard helper unavailable or timed out; degrade gracefully
}

Defensive patterns

Strategy: try-catch

Validate before calling

if (Application.Driver?.Clipboard?.TryGetClipboardData (out string text) == true)
{
    // use text — Try* methods do not throw on timeout/unsupported
}

Type guard

static bool ClipboardReadSafely (out string text) =>
    Application.Driver?.Clipboard?.TryGetClipboardData (out text) == true;

Try / catch

try
{
    string text = Application.Driver.Clipboard.GetClipboardData ();
}
catch (TimeoutException ex)
{
    Logging.Warning ($"Clipboard helper timed out: {ex.Message}");
    text = string.Empty;
}

Prevention

Prefer TryGetClipboardData/TrySetClipboardData to avoid throws on timeout.
Use a clipboard helper that does not hold the selection open (avoid raw xclip over SSH).
Ensure a responsive clipboard daemon is running in the session.

When it happens

Trigger: The clipboard helper (xclip, xsel, pbcopy/pbpaste, wl-copy/wl-paste, or a bash -c wrapper) hangs — e.g. waiting on an X11 selection that never resolves, a dead clipboard daemon, or a frozen display server; the helper prompting for something interactively that blocks.

Common situations: xclip holding the clipboard selection open until another process claims it (classic xclip behavior over SSH); a stale clipboard manager; a wedged Wayland compositor; slow network filesystems affecting the helper's startup.

Understand the failure class

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of tui-cs/Terminal.Gui@2e47b11478 (2026-08-13). Data as JSON: /api/errors/4be94fe952f72ab4. Report an issue: GitHub.