build-depends-indep missing?

Hi,

this one puzzles me: http://launchpadlibrarian.net/14622202/buildlog_ubuntu-intrepid-amd64.hs-plugins_1.2-1_FAILEDTOBUILD.txt.gz

Obviously, the build-depends-indep aren't installed, so the build fails. However after looking at debian/rules, I'm a bit puzzled, as the build failure results from build-indep/build-indep-stamp getting called, which imho can only happen via invoking the binary target (and 7.3 says that build-depends-indep must be there when calling binary). What target is getting invoked there? Any other hints?

Thanks,
     Stefan.