With bb9dba56aca7e4bd3546ad1fa3256bfc8955c47e, I introduced a pitiful regression in "rpm-based" Ansible installation (via yum or dnf). This fix is part of GH-6654
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.