The scons build for kdissert needs COPY not symlink the documentation files. Otherwise, the install step copies the newly built KDE-style documentation into /usr/kde/3.4/share/doc/HTML/en/kdissert (for example) and two of the files are actually symlinks to the /var/tmp/portage tree where the product was built! This was the kdissert-1.0.5 ebuild.
I looked a bit deeper and it looks like bksys/generic.py has lenv.SetOption('duplicate', 'soft-copy') which causes soft links (symlinks) to be used rather than copying the files. I changed it to lenv.SetOption('duplicate', 'copy') and it fixed my problem.
Thanks for your report, Alan.