box64 is a userspace x86_64 emulator for arm64… with a twist. Simply speaking, when it doesn’t emulate x86_64 instructions it attempts to load native versions of libraries the binary requires, enabling higher performance and compatibility.
It is best served as a binfmt.d handler, directly integrating the x86_64 execution support into the OS through a kernel interface. Though this kernel interface isn’t in use directly within the snap yet (no setup procedure right now) it is on the roadmap.
box64 needs access to various system files usually inaccessible to confined apps since the intended usecase is to run applications downloaded from the web, and those apps might require any possible combination of permissions unavailable to strict confinement, including access to either system-wide multiarch x86_64 libraries or some located in an arbitrary sysroot path. As such, I would like to request an exception for classic confinement for box64-with-gl4es.