App crashes on choosing Volume from system tray menu after selecting streaming device

I've installed mkchromecast-git (version r1213.c046ba2f-1) from the AUR on Arch Linux.

If I select the streaming device (Google Home Mini) and then choose Volume from the system tray menu, the application crashes. When I run mkchromecast -t from the terminal, it produces the following error:

Traceback (most recent call last):
  File "/usr/share/mkchromecast/mkchromecast/systray.py", line 602, in volume_cast
    self.sl.setValue(round((self.cast.status.volume_level * self.maxvolset), 1))
TypeError: setValue(self, int): argument 1 has unexpected type 'float'
Aborted (core dumped)

However, there's no such issue if I choose Volume from the system tray menu without selecting any streaming device.