I assume it means coming up with a reasonable emulation of signals, fork(), etc. Something similar to how WSL1 works, since Fuchsia is significantly different from POSIX in some areas.
Do you know where we could read about the internals of Fuchsia?
yes but are they not re-using the MS put it a container strategy of how they handle the differences between their specific kernel and hoe Linux kernel and Unix POSIX standards are implemented?
This wouldn't solve the problem. It would push the problem one level lower.