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

Failed to find active pane

Error message

Failed to find active pane

What it means

Returned in the mouse handler's stop-resize path (err_context 'failed to stop resize') when, after a mouse-resize gesture ends without resizing, tab.get_active_pane_id cannot resolve the client's active pane. The code wants to compare/focus the pane under the cursor, but without an active pane id it errors out instead.

Source

Thrown at zellij-server/src/tab/mouse_handler.rs:894

            MouseAction::NoAction => Ok(MouseEffect::default()),
        }
    }

    fn execute_stop_resize(
        tab: &mut Tab,
        position: Position,
        client_id: ClientId,
    ) -> Result<MouseEffect> {
        let err_context = || "failed to stop resize";
        let never_resized = Self::stop_pane_resize_with_mouse(tab, position, client_id)
            .with_context(err_context)?;
        if never_resized {
            let pane_id_at_position = Self::get_pane_at(tab, &position, false)
                .with_context(err_context)?
                .map(|p| p.pid());
            let active_pane_id = tab
                .get_active_pane_id(client_id)
                .ok_or_else(|| anyhow!("Failed to find active pane"))?;
            if let Some(pane_id) = pane_id_at_position {
                if pane_id != active_pane_id {
                    Self::focus_pane_at(tab, &position, client_id).with_context(err_context)?;
                }
            }
        }
        Ok(MouseEffect::state_changed())
    }

    fn execute_focus_pane(
        tab: &mut Tab,
        position: Position,
        client_id: ClientId,
    ) -> Result<MouseEffect> {
        let err_context = || "failed to focus pane";
        clear_hover_for_client(tab, client_id);
        let active_pane_id_before = tab
            .get_active_pane_id(client_id)

View on GitHub (pinned to 98a0837077)

Solutions

1. Click once on a live pane to re-establish focus, then retry the gesture
2. Verify the tab still has panes; open one if the tab is empty
3. If this recurs during normal mouse use, upgrade zellij and check for pane-exit race fixes
4. Capture logs with `zellij --debug` to identify which pane-exit path left focus empty

Example fix

// before
let active_pane_id = tab
    .get_active_pane_id(client_id)
    .ok_or_else(|| anyhow!("Failed to find active pane"))?;

// after: skip focus comparison when there is nothing focused
let Some(active_pane_id) = tab.get_active_pane_id(client_id) else {
    return Ok(MouseEffect::default());
};

// guard the focus comparison after a resize gesture
if tab.get_active_pane_id(client_id).is_none() {
    return Ok(MouseEffect::default());
}

fn has_active_pane(tab: &Tab, client_id: ClientId) -> bool {
    tab.get_active_pane_id(client_id).is_some()
}

// mouse-event entry point: log and continue on transient focus gaps
if let Err(e) = tab.handle_mouse_event(&event, client_id) {
    log::debug!("mouse event dropped: {e:#}");
}

When it happens

Trigger: Releasing a mouse button that was (or looked like) a pane-resize drag on a tab where the client has no resolvable active pane - empty tab, focus not yet assigned, or the focused pane exited during the drag.

Common situations: Mouse-up after a long drag during which the focused pane's process exited; clicking on a tab whose panes all closed; using the mouse immediately after attaching, before focus settled; automated mouse-event injection into an empty tab.

Related errors

• Could not find editor pane to replace - is no pane focused?
• failed to find active pane id for client {client_id}
• no active pane for client {client_id}
• Failed to find pane {pane_id:?}
• Failed to find pane {active_pane_id:?}

AI-assisted analysis of zellij-org/zellij@98a0837077 (2026-08-16). Data as JSON: /api/errors/303f2ddd1f97fd9e. Report an issue: GitHub.