It may not be that big a task. How much code do you really need to run a container instance? If you could get an airtight Xen-like system, you might not need much of an OS inside each container. Xen already does memory allocation, CPU dispatching, I/O handling, timer handling, and message passing, which is all an OS really needs.

Rust programs running on "libnative" do not, I think, use "libc" any more.