[gentoo-user] rebuild of graphviz failed

Hi folks,

after the last update, rebuild of graphviz failed with:

 * Package:    media-gfx/graphviz-2.26.3-r4
 * Repository: gentoo
 * Maintainer: graphics@g.o
 * USE:        abi_x86_64 amd64 cairo doc elibc_glibc examples gtk kernel_linux nls perl python userland_GNU
 * FEATURES:   ccache preserve-libs sandbox userpriv usersandbox
>>> Unpacking source...
>>> Unpacking graphviz-2.26.3.tar.gz to /var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/work
>>> Source unpacked in /var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/work
>>> Preparing source in /var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/work/graphviz-2.26.3 ...
 * Applying graphviz-2.26.3-libtool.patch ...
 [ ok ]
 * Applying graphviz-2.26.3-automake-1.11.2.patch ...
 [ ok ]
cp: cannot stat '/usr/share/libtool/config/install-sh': No such file or directory
 * ERROR: media-gfx/graphviz-2.26.3-r4::gentoo failed (prepare phase):
 *   (no error message)
 * 
 * Call stack:
 *     ebuild.sh, line  93:  Called src_prepare
 *   environment, line 5681:  Called die
 * The specific snippet of code:
 *           cp "${EPREFIX}"/usr/share/libtool/config/install-sh config || die;
 * 
 * If you need support, post the output of `emerge --info '=media-gfx/graphviz-2.26.3-r4::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=media-gfx/graphviz-2.26.3-r4::gentoo'`.
 * The complete build log is located at '/var/log/portage/media-gfx:graphviz-2.26.3-r4:20150209-234745.log'.
 * The ebuild environment file is located at '/var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/temp/environment'.
 * Working directory: '/var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/work/graphviz-2.26.3'
 * S: '/var/tmp/portage/portage/media-gfx/graphviz-2.26.3-r4/work/graphviz-2.26.3'

Any recommendations how I can solve this problem?

Regards
wabe