I tried building the current package and couldn't figure it out. It seems to me the most up to date code is in upstream/trunk, but there is no debian/ directory there. When I tried to copy the debian directory from debian/trunk/, the build could not complete, because the manpage changed format. So I needed this, at least:
-Build-Depends-Indep: debhelper (>= 4.1.16)
+Build-Depends-Indep: debhelper (>= 4.1.16), docbook2x
Otherwise it worked fine by copying the directory over, but I ask myself how we're supposed to build that package...