Current compton upstream is long unmaintained, but i discovered active fork: https://github.com/yshui/compton which i discovered looking news about recent compiz release at www.opennet.ru.
another source : https://www.phoronix.com/forums/forum/phoronix/latest-phoronix-articles/1088916-nvidia-lands-fix-to-avoid-high-cpu-usage-when-using-the-kde-desktop?p=1088948#post1088948
Created attachment 573388 [details] compton-6.ebuild (update, yshui fork) Here is an updated ebuild for that fork. Signed-off-by: Colin Geniet <colin.geniet@gmail.com>
The fork has been renamed picom
https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=506a537dcfe3df91764dfd4392a53d417281b6e2