libmachine/drivers/plugin/localbinary/plugin.go
func driverPath(driverName string) string {
	for _, coreDriver := range CoreDrivers {
		if coreDriver == driverName {
			if CurrentBinaryIsDockerMachine {
				return os.Args[0]
			}

			return "docker-machine"
		}
	}

	return fmt.Sprintf("docker-machine-driver-%s", driverName)
}
func driverPath(driverName string) string {
	for _, coreDriver := range CoreDrivers {
		if coreDriver == driverName {
			if CurrentBinaryIsDockerMachine {
				return os.Args[0]
			}

			return "docker-machine"
		}
	}

	return fmt.Sprintf("docker-machine-driver-%s", driverName)
}
// driverPath finds the path of a driver binary by its name.
//  + If the driver is a core driver, there is no separate driver binary. We reuse current binary if it's `docker-machine`
// or we assume `docker-machine` is in the PATH.
//  + If the driver is NOT a core driver, then the separate binary must be in the PATH and it's name must be
// `docker-machine-driver-driverName`