As per summary, graphviz ebuilds does not depend on autotools (they use autoreconf rather than eautoreconf, so it does not use autotools eclass for the automatic dependencies, that would be suggested). Also, sys-devel/libtool should be a runtime dependency because the following files links to libltdl.so: libltdl.so.3 /usr/lib64/graphviz/libgvc.so.2.0.0 libltdl.so.3 /usr/lib64/graphviz/tcl/libtcldot.so.0.0.0 libltdl.so.3 /usr/lib64/graphviz/libgvc_builtins.so.2.0.0 Thanks
This is fixed already in 2.8-r2, latest stable for almost all arches (almost).