Upstream master moved to cmake a few days ago: https://aomedia.googlesource.com/aom/+/e07a675f71e7b784aef57fe86ffca01c7365d07e The current ebuild fails with a "configure: no such file or directory".
good news.
You can find a working libaom-9999-r1 in my overlay: https://github.com/stefantalpalaru/gentoo-overlay
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=fa8ef6b1bdf230f75465f93ca90371abce5f2219 commit fa8ef6b1bdf230f75465f93ca90371abce5f2219 Author: Alexis Ballier <aballier@gentoo.org> AuthorDate: 2018-02-22 13:40:06 +0000 Commit: Alexis Ballier <aballier@gentoo.org> CommitDate: 2018-02-22 13:40:15 +0000 media-libs/libaom: cleanup ebuild and convert to cmake. Closes: https://bugs.gentoo.org/645142 Package-Manager: Portage-2.3.24, Repoman-2.3.6 media-libs/libaom/libaom-9999.ebuild | 128 ++++++++++++----------------------- 1 file changed, 43 insertions(+), 85 deletions(-)