I followed the given instructions on my MacOSX 10.15.7 following brew installs of vagrant and virtualbox, but running vagrant up resulted in

    ==> default: Clearing any previously set network interfaces...
    ==> default: Preparing network interfaces based on configuration...
        default: Adapter 1: nat
    ==> default: Forwarding ports...
        default: 22 (guest) => 2222 (host) (adapter 1)
    ==> default: Booting VM...
    ==> default: Waiting for machine to boot. This may take a few minutes...
        default: SSH address: 127.0.0.1:2222
        default: SSH username: vagrant
        default: SSH auth method: private key
        default: Warning: Remote connection disconnect. Retrying...
        ...
    Timed out while waiting for the machine to boot. This means that Vagrant was unable to communicate with the guest machine within the configured ("config.vm.boot_timeout" value) time period.

I cannot find any config.vm.boot_timeout in Vagrantfile