tui-cs/Terminal.Gui · error · NotSupportedException

"{_xclipPath} {xclipArgs}" failed.

Error message

"{_xclipPath} {xclipArgs}" failed.

What it means

Thrown by UnixClipboard.GetClipboardDataImpl when invoking xclip to read the clipboard selection raises an exception (e.g. process failure), wrapping the original exception. It is a NotSupportedException. Note: IsSupported is determined at construction by checking that xclip exists; this error means xclip was found but the read operation itself failed at runtime.

Source

Thrown at Terminal.Gui/Drivers/UnixHelpers/UnixClipboard.cs:39

    public override bool IsSupported { get; }

    protected override string GetClipboardDataImpl ()
    {
        string tempFileName = Path.GetTempFileName ();
        string xclipArgs = "-selection clipboard -o";

        try
        {
            (int exitCode, string _) = _processRunner.Bash ($"{_xclipPath} {xclipArgs} > {tempFileName}", waitForOutput: false);

            if (exitCode == 0)
            {
                return File.ReadAllText (tempFileName);
            }
        }
        catch (Exception e)
        {
            throw new NotSupportedException ($"\"{_xclipPath} {xclipArgs}\" failed.", e);
        }
        finally
        {
            File.Delete (tempFileName);
        }

        return string.Empty;
    }

    protected override void SetClipboardDataImpl (string text)
    {
        string xclipArgs = "-selection clipboard -i";

        try
        {
            _processRunner.Bash ($"{_xclipPath} {xclipArgs}", text);
        }
        catch (Exception e)

View on GitHub (pinned to 2e47b11478)

Solutions

1. Check Clipboard.IsSupported before using clipboard APIs and degrade gracefully.
2. Ensure an X session is available (set DISPLAY, use ssh -X, or run under XWayland).
3. Install/verify xclip is functional: run `xclip -selection clipboard -o` manually.

Example fix

// before
string text = Clipboard.GetText();

// after
string text = Clipboard.IsSupported ? Clipboard.GetText() : string.Empty;

if (!Clipboard.IsSupported) return string.Empty;

static bool ClipboardReady() => Clipboard.IsSupported;

try { return Clipboard.GetText(); } catch (NotSupportedException) { return string.Empty; }

When it happens

Trigger: Calling Clipboard.GetText (or GetClipboardDataImpl) on Linux when xclip is installed but the read fails: no X display, xclip not in an active X/Wayland session, permission denied, or xclip killed.

Common situations: Running a Terminal.Gui app over SSH without X forwarding, headless/CI environments, Wayland without XWayland, or xclip crashes/permission issues.

Related errors

• "{_xclipPath} {xclipArgs} < {text}" failed
• Failed to copy from the OS clipboard.
• Failed to paste to the OS clipboard.
• Process timed out. Command line: {process.StartInfo.FileName
• Failed to get screenBuffer console mode, error code: {Marsha

AI-assisted analysis of tui-cs/Terminal.Gui@2e47b11478 (2026-08-13). Data as JSON: /api/errors/334f8424c6a25a44. Report an issue: GitHub.