test.lua

function runString_debug(s, d)
  local u,v=loadstring(s)
  if (v~=nil) then
    print(v)
  else
    -- Set up a debug hook.
    if d==1 then
      local function callb()
        print("called callb")
        error()
      end
      debug.sethook(callb,"l")
    end

    print "DOES THE CODE EVER GET HERE?"
    local status, err=pcall(u)
    print(status)
    print(err)
  end
end

runString_debug("for i=1,10 do print(i) end", 1)
print "DOES IT GET HERE?"