"The easiest way to build Ingen from SVN is to build the entire http://svn.drobilla.net/lad repository (since there are dependencies between the various projects)."
Unfortunately there is wide gulf between the "easiest way to build" applications and the easiest way to install and manage them.
I guess Mark's point is that it has been impossible to build ingen from the AUR scripts for some time, which is sadly true. Trying to mix svn of some of drobilla libraries with AUR or Arch packages of those libraries, or even the full svn tree with apps that depend on the official packages, quickly results in a mess.