$ vagrant plugin update
Updating installed plugins...
Fetching: vagrant-hostmanager-1.8.7.gem (100%)
Fetching: vagrant-hostsupdater-1.0.2.gem (100%)
Fetching: vagrant-proxyconf-1.5.2.gem (100%)
Fetching: vagrant-share-1.1.9.gem (100%)
Fetching: micromachine-2.0.0.gem (100%)
Fetching: vagrant-vbguest-0.15.0.gem (100%)
Updated 'vagrant-hostmanager' to version '1.8.7'!
Updated 'vagrant-share' to version '1.1.9'!
Updated 'vagrant-vbguest' to version '0.15.0'

$ vagrant vbguest --status
[default] GuestAdditions versions on your host (5.2.2) and guest (5.1.30) do not match.


$ vagrant vbguest
[default] GuestAdditions versions on your host (5.2.2) and guest (5.1.30) do not match.
Copy iso file /Applications/ into the box /tmp/VBoxGuestAdditions.iso
Mounting Virtualbox Guest Additions ISO to: /mnt
mount: /dev/loop0 is write-protected, mounting read-only
Installing Virtualbox Guest Additions 5.2.2 - guest version is 5.1.30
Verifying archive integrity... All good.
Uncompressing VirtualBox 5.2.2 Guest Additions for Linux........
VirtualBox Guest Additions installer
Removing installed version 5.2.2 of VirtualBox Guest Additions...
Copying additional installer modules ...
Installing additional modules ...
VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel modules.
VirtualBox Guest Additions: Running kernel modules will not be replaced until the system is restarted
VirtualBox Guest Additions: Starting.
VirtualBox Guest Additions: modprobe vboxsf failed
An error occurred during installation of VirtualBox Guest Additions 5.2.2. Some functionality may not work as intended.
In most cases it is OK that the "Window System drivers" installation failed.
Redirecting to /bin/systemctl start  vboxadd.service
Redirecting to /bin/systemctl start  vboxadd-service.service
Job for vboxadd-service.service failed because the control process exited with error code. See "systemctl status vboxadd-service.service" and "journalctl -xe" for details.
Unmounting Virtualbox Guest Additions ISO from: /mnt