If you're getting an error while trying to install Docker on an older MacBook (e.g. MacBook 7,1 8,1 9,1) here's how to solve it.

Environment Error

Incompatible CPU detected

We are sorry, but your hardware is incompatible with Docker Desktop.

Docker requires a process with virtualization capabilities and hypervisor support.

You can verify that your Processor is incompatible by checking the output of the following command:

sysctl kern.hv_support

If the output is kern.hv_support: 0, then you have confirmed you have an incompatible MacBook Pro.

But no worries, just download the "Docker Toolbox" for Mac.

From here https://docs.docker.com/toolbox/toolbox_install_mac/

And you're good to go. You don't even need to manually install VirtualBox, it does it by itself.