xnview is distributed by its author as a binary with some static and some dynamic linking. There are presently 2 versions available with different libstdc++ dependancies: XnView-x86-unknown-linux2.x-static-fc4.tgz => libstdc++.so.6 XnView-x86-unknown-linux2.x-static.tgz => libstdc++-libc6.1-1.so.2 xnview-1.70-r1.ebuild uses the first version without checking for libstdc++.so.6 I'm not sure from which package libstdc++.so.6 comes from (gcc-3.4 ?) so I can't propose a patch to the ebuild for now.
*** This bug has been marked as a duplicate of 124695 ***