Polybar was originally built with Linux in mind, so certain modules do
not function in FreeBSD.

Working modules:
- bspwm
- cpu
- date
- i3
- memory
- script
- text
- xkeyboard
- xwindow

Broken modules:
- filesystem
- network (requires wireless_tools)
- temperature (requires /sys/class/thermal/* in sysfs)
- volume (requires full alsa, not a wrapper)
- menu (does not show up)
- xbacklight
- xworkspaces

Not tested:
- backlight
- battery
- github
- ipc
- mpd
