Please consider adding 'select PID_NS' to the 4567_distro-Gentoo-Kconfig.patch under the GENTOO_LINUX_PORTAGE option. This is required for the new pid-sandbox option present in sys-apps/portage-2.3.53
commit 61c500b9e4094cd771f8d5213004717bda3edfcc (HEAD -> master, origin/master, origin/HEAD) Author: Mike Pagano <mpagano@gentoo.org> Date: Fri Dec 28 18:58:06 2018 -0500 proj/linux-patches: Select PID_NS to support FEATURES=pid-sandbox For portage: >=sys-apps/portage-2.3.53 See bug #673896 Signed-off-by: Mike Pagano <mpagano@gentoo.org> In master, will gradually move through currently supported branches.
This made it in for 4.19.13, and will be in the next releases of genpatches for 4.4, 4.9, 4.14 and 4.20.