'Tool openocd is not available on your operating system' when adding board via Board Manager on Arduino IDE

[rayhaanq]

I've got a Raspberry Pi 3 B+ that I'm trying to use to program my Redbear BLE Nano v2 by following the instructions here https://github.com/redbear/nRF5x/blob/master/nRF52832/docs/Arduino_Board_Package_Installation_Guide.md I get an error Tool openocd is not available on your operating system when trying to install the nRF52832 board, but I already have openocd installed on my system. Is there any way to get this working?