If you take look onto /usr/lib64/itkConfig.sh and coutnerpart from itclConfig.sh it contains completely stupid variables: ITK_BUILD_LIB_SPEC='-L/var/tmp/portage/dev-tcltk/itk-3.4_pre20090417-r1/work/incrTcl/itk -litk3.4' It should provide proper -L content, same apply for the other variables. Sed that in install phase, again as it is broken in stable it would be rather nice to have it fixed there asap. (I know we work around this by the env variables, but it would be rather nice to have it fixed their way so I don't have to rape other configure scripts to find it properly on gentoo)
These are the BUILD_LIB variables. In contrast the # String to pass to linker to pick up the Itk library from its # installed directory. itk_LIB_SPEC='-L/usr/lib64/itk3.4 -litk3.4' ITK_LIB_SPEC='-L/usr/lib64/itk3.4 -litk3.4' are sane.