So guix doesn't work inside a vm - because /gnu/store is mounted
readonly. To be able to offload arm builds once guix system vm
--system=armhf-linux works, /gnu/store needs to be writeable.
Can multiple daemons concurrently use the same store?
or alternatively, can we move the
(unless (zero? (system* unionfs "-o"
"cow,allow_other,use_ino,suid,dev,max_files=65536"
"/rw-root=RW:/real-root=RO"
"/root"))
(error "unionfs failed"))
to after the 9p filesystems have been mounted, so that the unionfs
allows writing to /gnu/store too?
