My module lua-MessagePack is a good use case for lua-5.3.0-work1. I experiment a specific version which works only with it, see the diff https://github.com/fperrad/lua-MessagePack/commit/a1e3221ee3b0a40f9698d4166db6 All `math.floor` calls are removed. François Note : the `master` branch works fine with Lua 5.1, 5.2, 5.3.0-work1 and LuaJIT