The scigraphica ebuild is failing on my machine because it can't locate
'libgdk_imlib' on my machine, but all dependencies seem satisfied
(>=x11-libs/gtk+extra-0.99.17, >=dev-python/Numeric-20.3, >=dev-libs/libxml-1.8.16).
I haven't managed to work out which package builds libgdk_imlib, but it is
definitely not on my machine...
Ok, i bumped the version to -r1 and added >=media-libs/imlib-1.9.14 to depend.
This should do the trick for you.
Please test and report if it works. The ebuild is currently masked, i'll unmask it if it works for you.