We have started seeing occasional shutdown failures on openSUSE Tumbleweed with Virtualbox inside a qemu virtual machine, where `shutdown -h now` would return nil. While the machine is successfully turned off, the command fails and vagrant reports an error. This commit changes the shutdown command to launch in the background which also triggers a shutdown, but always succeeds.
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.