All you should need to do:
MONO_VERSION=3.2.6 vagrant up
After a long wait a .deb
will magically appear!
If you really want to build it on your host you can just call the scripts directly. You'll have to make sure you have all required dependencies yourself.
./build-mono-package.bash 3.0.10
./build-xsp-package.bash 3.0.11