Needs a new VM tracking trunk.
Maybe target 10.14?
Blocker for #2384
Note to self, had to restore the older 10.11.x build VM from a snapshot as it broke with the virtualbox 6.1 update. Another 10.11.x VM, originally based on the same install as the broken one, does work but its disk image was too small to install xcode.
Here's how to increase the VDI size and get macos to grow the partition (the hard part):
VBoxManage modifyhd OSX\ Dev.vdi --resize 65536
sudo qemu-nbd -c /dev/nbd0 OSX\ Dev.vdi sudo gparted /dev/nbd0 #(click OK to fix) sudo qemu-nbd -d /dev/nbd0
Do not try to resize with gparted, it won't work.
diskutil resizeVolume /dev/disk??? 64Gsince the GUI won't do it
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2422