There are a lot of neat tools available to program/hack/reprogram/work with this nifty little Bluefruit Feather board! One of them is the Arduino-IDE, a development environment that allows you create and then flash your new programs to the board. I was faithfully following along in the Bluefruit Feather Arduino setup instructions, which are here:

https://learn.adafruit.com/bluefruit-nrf52-feather-learning-guide/arduino-bsp-setup

But I ran into an issue right out of the gate with step #1: Install the Arduino-IDE. In the instructions it states that it must be version 1.6.12+, something that I missed the first go around. Using Ubuntu's regular package manager, I just used apt-get install to download  and install the Arduino-IDE.

When I moved on to the next step, where you are to put in the "Additional Board Manager URL", I ran into a snag. There was no place to do that. The block that should have been displayed there in the preferences didn't exist. So I re-read the instructions. Turns out that the Ubuntu repository only has Arduino-IDE version 1.0.5! So it was a little out of date.

Fortunately, on the bsp setup page above, there was a direct link to download and install the newer version of the software. A quick download, unzip/untar, and a quick \$ sh ./install.sh command allowed me to install the latest version in minutes. Hopefully you can avoid that same pitfall. Now, back to those instructions....

Linux - keep it simple.