According to changes http://tux.rainside.sk/apache//httpd/CHANGES_2.4.18: *) mod_http2: required minimum version of libnghttp2 is 1.2.1 Currently we have https://gitweb.gentoo.org/repo/gentoo.git/tree/www-servers/apache/apache-2.4.18.ebuild?id=755e0c5b293464e9c9cc0c4f9cbf426f9080b397: DEPEND+="apache2_modules_http2? ( >=net-libs/nghttp2-1.0.0 )"
commit a740d93a05bf8823ebaac41ecbb0e55c1bc4c824 Author: Lars Wendler <polynomial-c@gentoo.org> Date: Mon Dec 14 13:39:37 2015 www-servers/apache: Raised minimum required version of nghttp2 to version 1.2.1 as reuqested in bug #568224 Package-Manager: portage-2.2.26 Signed-off-by: Lars Wendler <polynomial-c@gentoo.org>