new build setup for macos

[Antoine Martin]

Needs a new VM tracking trunk.

Maybe target 10.14?

Blocker for #2384

[Antoine Martin]

See #2505

[Antoine Martin]

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):

• resize VDI to 64GB:

VBoxManage modifyhd OSX\ Dev.vdi --resize 65536

• fix GPT with gparted:

  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.

• Attach the disk to another VM (make it hotplug, whatever to try to not boot on it)
• resize the partition with diskutil resizeVolume /dev/disk??? 64G since the GUI won't do it

Helpful links:

• ​Expand virtual hard drive
• ​Grow HFS+ partition on Mac OS X without Disk Utility