The ebuild states the license is "Apache-2.0 OSGi-Specification-2.0" but the tarball only talks about Apache-2.0. Are you sure that the OSGi-Specification-2.0 licence is relevant?
Indeed. epsilon work # pwd /var/tmp/portage/dev-java/osgi-core-api-5.0.0/work epsilon work # head -5 LICENSE Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ commit fda2a8a (HEAD, master) Author: Patrice Clement <monsieurp@gentoo.org> Date: Sat Sep 5 09:42:38 2015 +0000 dev-java/osgi-core-api: Switch license to Apache-2.0. Fixes bug 559526. Package-Manager: portage-2.2.18 Signed-off-by: Patrice Clement <monsieurp@gentoo.org>