Please build lua-socket (including lua5.1-socket) for EPEL8. This is one of dependencies for Knot Resolver.
It'd also be great to update the `lua-socket-compat` name to the new package naming convention: `lua5.1-socket` (see https://pagure.io/packaging-committee/issue/878#comment-566612 for docs; spec change example - https://src.fedoraproject.org/rpms/lua-lpeg/c/cb196b95200035fe150eb7bcd17b8deeb29f5791?branch=master )
In difference to RHEL/CentOS 7, the lua-socket package is now part of RHEL/CentOS 8. Thus branching of lua-socket for EPEL 8 isn't possible. The correct way is to create a new package "lua5.1-socket" and to create a new package review request for it.