linebender/druid · error

More than one path received for single selection

Error message

More than one path received for single selection

What it means

druid-shell's GTK file dialog can return multiple filenames when multi-selection is enabled in the native chooser. If the dialog was opened with `multi_selection: false` but the chooser still returns more than one file, the API contract (exactly one path for single selection) is broken, so an anyhow error is returned.

Solutions

1. Ensure `FileDialogOptions.multi_selection` is correctly propagated when constructing the GTK FileChooser (select_folder/select_file vs select-multiple action)
2. Druid (>=0.7/0.8) restricts FileDialog usage to directory selection only — prefer `FileDialog::open_directory` and update code that expects file multi-selection
3. Handle the returned Result gracefully (treat like cancellation) and/or filter to the first file if your app can tolerate it

Example fix

// before
let paths: Vec<PathBuf> = dialog.get_paths().unwrap(); // assumes exactly one
// after
match get_file_dialog_path(...) {
    Ok(mut paths) if paths.len() == 1 => use(paths.remove(0)),
    _ => { /* cancelled or invalid selection */ }
}

// Validate options and results before use
assert_eq!(options.multi_selection, false);
match paths.len() {
    1 => use_path(paths[0].clone()),
    _ => cancel(),
}

match result { Err(e) if e.to_string().contains("More than one path") => { /* fall back to first path or cancel */ }, other => other }

When it happens

Trigger: Calling FileDialog with multi_selection disabled while the underlying GTK FileChooser is in a state allowing multiple selection (mismatch between druid's `FileDialogOptions` and the constructed chooser widget), then the user selects several files and accepts.

Common situations: Configuring options after the dialog was created or ignoring `multi_selection` when constructing the GTK chooser; user selecting multiple files (Ctrl/Shift-click) in a dialog that should be single-select; version drift where the options flag stopped being honored.

Understand the failure class

Background: Conflicting config options: "cannot be used together" — configuration validation errors across open-source libraries — this error's family across 162 libraries.

Related errors

• No path received for filename
• Tried to build a window without setting the handler
• The main thread status has already been claimed by thread
• acquire_input_lock was called on a WinHandler that did not…
• release_input_lock was called on a WinHandler that did not…

AI-assisted analysis of linebender/druid@0f8b1195e4 (2026-09-10). Data as JSON: /api/errors/cde8315803a58dcd. Report an issue: GitHub.

Appendix: source

Thrown at druid-shell/src/backend/gtk/dialog.rs:93

        if let Some(dt) = &options.default_type {
            if !found_default_filter {
                tracing::warn!("The default type {:?} is not present in allowed types.", dt);
            }
        }
    }

    if let Some(default_name) = &options.default_name {
        dialog.set_current_name(default_name);
    }

    let result = dialog.run();

    let result = match result {
        ResponseType::Accept => match dialog.filenames() {
            filenames if filenames.is_empty() => Err(anyhow!("No path received for filename")),
            // If we receive more than one file, but `multi_selection` is false, return an error.
            filenames if filenames.len() > 1 && !options.multi_selection => {
                Err(anyhow!("More than one path received for single selection"))
            }
            // If we receive more than one file with a save action, return an error.
            filenames if filenames.len() > 1 && action == FileChooserAction::Save => {
                Err(anyhow!("More than one path received for save action"))
            }
            filenames => Ok(filenames.into_iter().map(|p| p.into_os_string()).collect()),
        },
        ResponseType::Cancel => Err(anyhow!("Dialog was deleted")),
        _ => {
            tracing::warn!("Unhandled dialog result: {:?}", result);
            Err(anyhow!("Unhandled dialog result"))
        }
    };

    // TODO properly handle errors into the Error type

    dialog.destroy();

View on GitHub (pinned to 0f8b1195e4)