Comment 1 for bug 1565985

When I attempted to reprovision the instance, I saw a warn about guest additions, then an error when the vagrant attempted to mount the synced folder:

==> default: Machine booted and ready!
==> default: Checking for guest additions in VM...
    default: No guest additions were detected on the base box for this VM! Guest
    default: additions are required for forwarded ports, shared folders, host only
    default: networking, and more. If SSH fails on this machine, please install
    default: the guest additions and repackage the box to continue.
    default:
    default: This is not an error message; everything may continue to work properly,
    default: in which case you may ignore this message.
==> default: Checking for host entries
==> default: Mounting shared folders...
    default: /home/curtis/Work => /Users/curtis/Sites/Work
Failed to mount folders in Linux guest. This is usually because
the "vboxsf" file system is not available. Please verify that
the guest additions are properly installed in the guest and
can work properly. The command attempted was:

mount -t vboxsf -o uid=`id -u curtis`,gid=`getent group curtis | cut -d: -f3` home_curtis_Work /home/curtis/Work
mount -t vboxsf -o uid=`id -u curtis`,gid=`id -g curtis` home_curtis_Work /home/curtis/Work

The error output from the last command was:

mesg: ttyname failed: Inappropriate ioctl for device
/sbin/mount.vboxsf: mounting failed with the error: No such device

I sshed into the instances, downloaded guest additions, mounted it, installed build-essential, and installed the additions.
After halting and uping the instance, synced_folders worked without error.