zellij-org/zellij · warning · anyhow::Error

Failed to find pane at position

Error message

Failed to find pane at position

What it means

Returned in execute_stop_moving_floating_pane when get_pane_at finds no pane (tiled or floating, non-selectable included per the false flag) at the position where the mouse button was released. After a drag that never moved a pane, the handler tries to focus the pane under the cursor and there is none, so it errors.

Source

Thrown at zellij-server/src/tab/mouse_handler.rs:1089

        } else {
            Ok(MouseEffect::default())
        }
    }

    fn execute_stop_moving_floating_pane(
        tab: &mut Tab,
        position: Position,
        client_id: ClientId,
    ) -> Result<MouseEffect> {
        let err_context = || "failed to stop moving floating pane";
        let never_moved = tab.floating_panes.stop_moving_pane_with_mouse(position);
        if never_moved {
            let active_pane_id = tab
                .get_active_pane_id(client_id)
                .ok_or_else(|| anyhow!("Failed to find active pane"))?;
            let pane_id_at_position = Self::get_pane_at(tab, &position, false)
                .with_context(err_context)?
                .ok_or_else(|| anyhow!("Failed to find pane at position"))?
                .pid();
            if active_pane_id != pane_id_at_position {
                Self::focus_pane_at(tab, &position, client_id).with_context(err_context)?;
            }
        }
        Ok(MouseEffect::default())
    }

    fn execute_focus_on_hover(
        tab: &mut Tab,
        pane_id: PaneId,
        position: Position,
        client_id: ClientId,
    ) -> Result<MouseEffect> {
        let err_context = || format!("failed to focus pane on hover for client {client_id}");

        let is_selectable = tab
            .get_pane_with_id(pane_id)

View on GitHub (pinned to 98a0837077)

Solutions

  1. Release the drag over an actual pane, or simply click directly on the target pane afterward
  2. If it happens constantly at valid coordinates, check for layout/resize races or stale geometry - resize the window once to force a relayout
  3. Upgrade zellij; position-resolution fixes around floating panes land regularly
  4. For embedders injecting mouse events, verify positions are in viewport coordinates expected by the tab

Example fix

// before
let pane_id_at_position = Self::get_pane_at(tab, &position, false)
    .with_context(err_context)?
    .ok_or_else(|| anyhow!("Failed to find pane at position"))?
    .pid();

// after: release over empty space is a no-op, not an error
let pane_id_at_position = match Self::get_pane_at(tab, &position, false)
    .with_context(err_context)?
{
    Some(pane) => pane.pid(),
    None => return Ok(MouseEffect::default()),
};
Defensive patterns

Strategy: fallback

Validate before calling

// treat release over empty space as an acceptable no-op
match Self::get_pane_at(tab, &position, false)? {
    Some(pane) => { let pid = pane.pid(); /* compare and focus */ },
    None => return Ok(MouseEffect::default()),
}

Type guard

fn position_hits_pane(tab: &Tab, position: &Position) -> bool {
    // public approximation: tab.hit_pane(position).is_some()
    tab.get_pane_at(position).is_some()
}

Try / catch

// hit-testing misses are expected; never fail the whole mouse pipeline for them
let effect = match tab.handle_mouse_event(&event, client_id) {
    Ok(effect) => effect,
    Err(e) => { log::debug!("mouse release over empty area ignored: {e:#}"); MouseEffect::default() },
};

Prevention

When it happens

Trigger: Mouse-up over an area of the tab that contains no pane - the empty background of the tiled area, gaps between floating panes, or the tab's dead space - at the end of a would-be floating-pane drag.

Common situations: Releasing a click in the gap between panes or on the background; releasing outside all floating panes after toggling the floating layer; releases at coordinates invalidated by a concurrent resize/layout change; high-DPI/scroll-offset mismatches mapping the release position outside all panes.

Related errors

AI-assisted analysis of zellij-org/zellij@98a0837077 (2026-08-16). Data as JSON: /api/errors/589f2801d365c3b3. Report an issue: GitHub.