remove_connection_async: future never resolved on successful delete → TimeoutError crash on startup

[YoshKoz]

Environment

• App: proton-vpn-gtk-app 4.16.4
• Package: python-proton-vpn-network-manager (latest Arch/AUR)
• Python: 3.14.5
• NetworkManager: 1.56.1
• OS: Arch Linux (CachyOS)

Bug Description

On startup, protonvpn-app crashes with asyncio.exceptions.TimeoutError before the window appears.

Root cause is in killswitch/wireguard/nmclient.py — the _on_connection_removed callback calls connection.delete_finish(result) on success but never calls future_interface_removed.set_result(None). The future can only be resolved via the device-removed GLib signal. When no WireGuard kill switch interface is active (e.g. after reboot, or after manually deleting stale pvpn-killswitch-perm NM connections), that signal never fires and the 10-second asyncio timeout in _wrap_future triggers.

This affects both killswitch=2 (permanent, tries to enable) and killswitch=0 (disabled, tries to remove) on startup.

Traceback

File "/usr/bin/protonvpn-app", line 8, in <module>
    sys.exit(main())
File ".../proton/vpn/app/gtk/__main__.py", line 35, in main
    controller = Controller.get(executor, exception_handler)
File ".../proton/vpn/app/gtk/controller.py", line 74, in get
    executor.submit(controller.initialize_vpn_connector).result()
File ".../proton/vpn/core/vpnconnector.py", line 288, in initialize_state
    await self._update_state(state)
File ".../proton/vpn/connection/states.py", line 196, in run_tasks
    await self.context.kill_switch.disable()
File ".../killswitch/wireguard/wgkillswitch.py", line 76, in disable
    await self._ks_handler.remove_killswitch_connection()
File ".../killswitch/wireguard/killswitch_connection_handler.py", line 291, in _remove_connection
    await _wrap_future(self.nm_client.remove_connection_async(connection))
File ".../killswitch/wireguard/killswitch_connection_handler.py", line 56, in _wrap_future
    return await asyncio.wait_for(...)
asyncio.exceptions.TimeoutError

Affected Code

killswitch/wireguard/nmclient.py, remove_connection_async method:

def _on_connection_removed(connection, result, _user_data):
    try:
        connection.delete_finish(result)
        # BUG: future_interface_removed.set_result(None) is never called on success.
        # Future only resolves via device-removed signal, which never fires
        # if no WireGuard interface is currently active.
    except Exception as exc:
        future_interface_removed.set_exception(...)

Proposed Fix

def _on_connection_removed(connection, result, _user_data):
    try:
        connection.delete_finish(result)
        if not future_interface_removed.done():
            future_interface_removed.set_result(None)  # resolve on success
    except Exception as exc:
        future_interface_removed.set_exception(...)

Steps to Reproduce

1. Have killswitch set to 0 or 2 in ~/.config/Proton/VPN/settings.json
2. Ensure no active pvpnksintrf1 WireGuard interface exists (fresh boot or after removing stale NM connections)
3. Launch protonvpn-app — crashes immediately with TimeoutError

Workaround

None currently available without patching the source or downgrading Python.

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Bug reported via automated analysis using Claude Code