Some media packages need to access /dev/video and other related device nodes during build.  This often causes a sandbox violation and requires ebuild maintainers to add exceptions for those devices.

As drobbins  stated in FL-9287, "What would be even better is to have a chroot set up for building that only contains critical device nodes necessary, and not hardware-specific device nodes. If portage used this, we wouldn't need to mask out hardware devices on user's systems."

and later (to me) in Discord: "there is too much exposure of the local environment and devices to the build process in portage ".

This would resolve FL-6926