v1 was here:
https://www.redhat.com/archives/libguestfs/2019-November/msg00003.html
This version depends on:
https://www.redhat.com/archives/libguestfs/2019-November/msg00004.html
and this series:
https://www.redhat.com/archives/libguestfs/2019-November/msg00009.html
The delta has been reduced slightly because of changes made possible
by cleaning up and fixing the quit path in nbdkit. It's still a
fairly ugly and invasive patch however, so suggestions sought about
how to make it better.
Rich.