This is an auto-filed bug because media-libs/raspberrypi-userland-bin installs files with unresolved SONAME dependencies. The issue was originally discovered on amd64, but it may be reproducible on other arches as well. If you think that a different summary clarifies the issue better, feel free to change it. Attached build log and emerge --info.
Created attachment 641236 [details] build.log build log and emerge --info