Mac Vagrant up 报错？

➜ Homestead git:(master) vagrant up
The provider 'virtualbox' that was requested to back the machine
'homestead-7' is reporting that it isn't usable on this system. The
reason is shown below:

Vagrant could not detect VirtualBox! Make sure VirtualBox is properly installed.
Vagrant uses the VBoxManage binary that ships with VirtualBox, and requires
this to be available on the PATH. If VirtualBox is installed, please find the
VBoxManage binary and add it to the PATH environmental variable.

卡在这里了，郁闷。