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

Working modules:
- bspwm
- date
- github
- i3
- ipc (polybar-msg method does not seem to work)
- menu
- mpd
- script
- text
- xkeyboard
- xwindow
- xworkspaces (not extensively tested)

Broken modules:
- cpu
- filesystem
- memory
- network (requires wireless_tools)
- temperature (requires /sys/class/thermal/* in sysfs)
- volume (requires full alsa, not a wrapper)

Unknown:
- backlight
- battery
- xbacklight