If you install “build-essential” as per https://forum.audacityteam.org/t/building-audacity-2-1-2-on-ubuntu-15-10/40680/1 it might help.
It would be much better IMO to git clone Audacity (or build the 2.1.2 tarball) in your home folder.
Personally I self-build wxWidgets 3.0.2 from http://wxwidgets.org/downloads/ in my home directory, install that build of widgets (which installs to /usr/local) then a self-built Audacity should find your self-built wxWidgets. But you should be able to use system wxWidgets on 16.04.
The naming scheme for the “Audacity Team” daily builds on Launchpad is outside our control, but essentially they are packaged versions of the latest Audacity source code, so always unstable alpha builds except at release time.
Gale