Created attachment 435094 [details] emerge --info Explicit title.
Created attachment 435096 [details] emerge -pvq
Created attachment 435098 [details] build log
Created attachment 435100 [details] build env
Fixed, the fact that the qt5 packages were compiled with gles2 was the problem. Here's the odyssey https://github.com/hrydgard/ppsspp/issues/8772
Try with this pr https://github.com/gentoo/gentoo/pull/4342
No reply for 10 months, presuming solved. Please reopen if you can still reproduce it with current version.