Cannot use without a swap device

I have a system where xfce4-taskmanager terminates on startup with: xfce4-taskmanager: failed to get swap device count

The cause is a call in get_memory_usage to swapctl() with SWAP_NSWAP that treats a return of zero as an error. But zero is a valid return value meaning zero swap devices, not an error. My system happens to be configured with zero swap devices, which may be unusual, but is a legitimate configuration. On my system (OpenBSD 7.1), swapctl(SWAP_NSWAP) is always successful so there are no errors to handle.

xfce4-taskmanager should function on systems with no swap devices.