macOS Guest Additions do not include mount.vboxsf

[HI_Paul]

When successfully installing the Darwin guest additions, the mount.vboxsf tool is not included, while there is a source tree available and seemingly being built.

Steps to reproduce:

• Disable all security on macOS Catalina guest
• Insert the Guest Additions ISO
• Install Guest Additions
• mount -t vboxsf VboxShared /Users/Shared/Host result in a File Not Found error because /Library/Filesystems/vboxsf.fs does not exist

I also checked the contents of the .pkg and as far as I can tell, it does not contain any tools for mounting file systems. The source tree on the other hand does contain some kind of implementation in src/Vbox/Additions/darwin/VboxSF, which I unfortunately can't seem to manage to build because the build system does not seem to be compatible with Xcode 12.

As for some context: I am trying to set up a macOS Catalina build system to build Unreal Engine games on a Big Sur (and Windows) host. The VM should have a minimally sized main disk and should share the actual build tree with the host. I already have all this set up, using SMBFS to share the build tree and it is working ok, but network performance is only about 30MB/s, so builds take forever.

Therefore I am trying to mount shared folders in the macOS 10.15 Catalina guest in hopes they will give me better performance, somewhere in the range of the 400MB/s, the virtual disk in the VM provides. I already installed the guest additions successfully, but as far as I can see, they are missing the mount.vboxsf tool to actually mount the shared folders. I also tried to unpack the VboxDarwinAdditions.pkg, contained on the additions iso of multiple VirtualBox version, but the tool simply isn't there and is not being created. As per the source tree, there should be a tool available to mount the shared folders though, so I am guessing this is a bug in the build environment.

[galitsyn]

HI_Paul,

Shared Folders support for MacOS guests is currently incomplete. This is the reason we do not ship mount.vboxsf tool with Darwin Additions package.