Trouble getting started with Doppler dev on Ubuntu

Hello all! I’m just starting out with the Doppler and I’m having trouble loading into it via the Arduino IDE. I’m repeatedly getting a “Couldn’t find a Board on the selected port” error, while at the same time the Port option in the Tools menu is greyed out. I’ve got the Adafruit SAMD libraries loaded, along with the Dadamachines boards loaded and the Doppler is selected. The Doppler is happily blinking along the 0-F sequence, unless I double tap RST to go into bootloader mode.

I’m in Arduino 1.8.11 and Ubuntu 16.04.6. If there’s something obvious I’m missing, I’d be thrilled. Thanks in advance for any advice!

Well I was able to work past that, but now my inexperience with docker is catching up to me. I enter the container, and am able to change directories into a “PRJ” folder, but there’s nothing in it. I’m not sure if I’m supposed to manually move things into the container or if I’ve bodged the installation or setup.

Any advice is welcome.

It looks like it was a problem with the $MOUNTPOINT var. $($MOUNTPOINT) works, but the line from the does not. I’d be interested in knowing if this is a typo in the guide or if my machine is behaving differently than others’.