Gentoo's Bugzilla –
Attachment 393988 Details for
Bug 536652media-gfx/blender-2.72b-r2 with dev-libs/boost-1.56.0-r1 - .../work/blender-2.72b_build/bin/blender: error while loading shared libraries: libboost_filesystem.so.1.55.0: cannot open shared object file: No such file or directory