The latest Forklift now contains support for a CentOS 8 based Katello development environment. This environment comes with Pulp 3 only and can be enabled by copying the example from vagrant/boxes/99-local.yaml.example into vagrant/boxes/99-local.yaml.
The CentOS 8 Vagrant boxes come with a default disk size of 10GB. This will not support development environments. We have included the specification of disk_size: 40 for all CentOS boxes by default. As part of that work, there is now included a playbook that is automatically run when a user specifies disk_size parameter to their box definition. This will automatically grow the disk size to the specified amount. Thus, for anyone who wants a larger disk_size, you can set this parameter (for EL7, EL8 and Debian/Ubuntu) to whatever value you wish and the filesystem will expand accordingly.