Alternatively, you can try my Maverick project which is all setup for you: http://goodrobots.github.io/maverick/current/#/
You can download the Ubuntu VM version, load it up, and it already has ardupilot installed into /srv/maverick/code/ardupilot and precompiled for SITL. It has the necessary prereqs already installed so you can update the ardupilot code base (git pull origin) and recompiled as you want.
But installing a vanilla Ubuntu 16.04 should work. If it doesn’t, then the docs need to be updated.
Just make sure that you have all needed python / cygwin packets installed.
Which environment you are using now? Bear in mind that you need to keep your submodules updated too. ArduPilot stack depends on several submodules, uavcan is one of those.
NOTE: This will erase all local modifications! If getting in trouble, sometimes hard reset helps. I use following commands to reset my folder structures if needed (done in the top ArduPilot folder).
Sorry for the delay, I couldn’t post because of a “temporary hold” on my account. I have finally gotten a build environment going in VirtualBox Ubuntu. Nothing else worked for me with the available documentation. I guess this thread can be closed now, though I’ll have to open a new thread for some problems I’m having with the code…