Unable to debug program

local function trace(ignore, level)
level = type(level) == "number" and level
local errorLevel = 3 + (type(ignore) == "number" and ignore or 0)
local errorDiff = errorLevel
local errorPos
local result = {}
repeat
  errorPos = select(2, xpcall(function() error("@", errorLevel) end, function(shit) return shit end))
  if errorPos ~= nil then errorPos = errorPos:match("(.+): @") end
  if errorPos then
   table.insert(result, errorPos)
   errorLevel = errorLevel + 1
   if errorLevel - errorDiff == level then return result end
  end
until not errorPos
return result
end

local function ejj(ejjdata)
  print("Press a key to show error")
  os.pullEvent("key")
  local tracd = trace()
  print(ejjdata)
  for k,v in pairs(tracd) do
	print("- "..v)
	sleep(0.2)
  end
  return ejjdata--.."\n- "..table.concat(, "\n- ")
end

local function loadfunc(feil, name)
  local handel = fs.open(fs.combine(feil, ""), "r")
  if not handel then return false, "Unable to load "..feil end
  local kernelstr = handel.readAll()
  handel.close()
  return loadstring(kernelstr, name)
end

local function dofunc(feil, name, err, ...)
  local func, ejj = loadfunc(feil, name)
  if not func then return nil, ejj end
  local argz = {...}
  if err then return xpcall(function() func(unpack(argz)) end, err) else return pcall(func, unpack(argz)) end
end

local argz = {...}

dofunc(argz[1], "DebuggerD", ejj, unpack(argz, 2))