Thanks Rock,
I made a bionic VM without using the documented vagrant flow and used setup_host.sh, make PREBUILT=<image> BOARDS=Pynq-Z2 works without error.
I also tried with the vagrant bionic machine after recloning the repo into /workspace it has proceeded past the Error.
This step does not appear to be in the documentation, I expect it only matters for windows hosts as the /pynq mount is NTFS and hence the permission problem. I still don’t get your comments relating to the size of /pynq as it is on the windows host.
Thanks again.
Geoff.