lua-cqueues 20200726-1build1 (amd64 binary) in ubuntu lunar

 cqueues is a type of event loop for Lua, except it's not a classic
 event loop. It doesn't use callbacks—neither as part of the API nor
 internally—but instead you communicate with an event controller by
 the yielding and resumption of Lua coroutines using objects that
 adhere to a simple interface.