5Axis Kinetic from 2.8 on 2.7x

Well, you didn't follow the instructions.

in the directory ~/linuxcnc-dev/debian$

you need to run the command: ./configure uspace

after that you run: dpkg-checkbuilddeps

Yes, I followed the instructions exactly, and it asks me to do an "update" which does not work:P

Ok, that complicates things. So lets try if we can get the required key installed.

Import the key:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C9F836336AAD909E


try the update again:

sudo apt-get update

If this does not work we'll go back to dealing with the missing dependencies one by one.

it was not complicated enough ...

Exactly. Looks like BeagleBrainz had forgotten his password and had to change the key.

forum.linuxcnc.org/9-installing-linuxcnc...t-iso?start=0#165631

Lets try and see.

What should be done about an address being mentioned. I guess it depends on the case?