The ebuild for x11-libs/cairo-1.16.0 puts some functions that cairomm apparently requires (cairo_script_*) under the new USE flag utils. So, the cairomm ebuild needs to include it in its RDEPEND. Without those functions, cairomm still builds and installs, but building packages that depend on cairomm (such as inkscape) fails with link errors.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=76c3bd643515a6398f211c45b1c70a87341d3143 commit 76c3bd643515a6398f211c45b1c70a87341d3143 Author: Matt Turner <mattst88@gentoo.org> AuthorDate: 2018-10-30 14:00:51 +0000 Commit: Matt Turner <mattst88@gentoo.org> CommitDate: 2018-10-30 14:01:22 +0000 x11-libs/cairo: Build cairo script unconditionally Lots of reverse dependencies need it, at least optionally. Saving the lzo dependency is not a worthy goal, so let's just reenable it instead of forcing reverse dependencies to change. Closes: https://bugs.gentoo.org/669196 Closes: https://bugs.gentoo.org/669448 Closes: https://bugs.gentoo.org/669952 Signed-off-by: Matt Turner <mattst88@gentoo.org> x11-libs/cairo/{cairo-1.16.0.ebuild => cairo-1.16.0-r1.ebuild} | 3 +-- x11-libs/cairo/cairo-9999.ebuild | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-)