If we want to avoid libc, perhaps
https://gitlab.redox-os.org/redox-os/relibc/-/tree/master/src/platform/redox/redox-exec
could be published on crates.io, or integrated into redox_syscall. But
just calling into libc and letting relibc handle it is generally
fine.
Things like fork() are problematic from a safety standpoint if one
isn't careful (generally you don't want to do anything like allocation
between fork and exec), and the way this is handled could use some auditing.
But in any case, this make strace work again.