Your mail about /bin/sh also raises an interesting topic of paths. Do you want to change /dev/null and /servers/exec to some other (hash-derived I would imagine) paths? Sounds wild but you totally could!
You could then either patch glibc (and everyone who expects to find /dev/null at its usual place), or provide symlinks. But then again I don't know enough about Guix to judge here.
@civodul
Unfortunately all this wouldn't help you too much with bootstrapping from source, since you cannot do I/O easily on the Hurd like you can on Linux with a few instructions; you need to do RPCs and all that (even to get your argv). This is of course hidden from you when you're using glibc.
@janneke