local function f() return getfenv and getfenv(1) or _G end
print("sameenv", f() == getfenv(1), type(f()))
local function src(fn)
  if not (debug and debug.info) then return "nodbg" end
  local ok, a, b = pcall(debug.info, fn, "s")
  return tostring(ok) .. " " .. tostring(a) .. " " .. tostring(b)
end
print("pcall", src(pcall))
print("error", src(error))
print("type", src(type))
print("tostring", src(tostring))
print("setmetatable", src(setmetatable))
print("loadstring", src(loadstring))
print("string.byte", src(string.byte))
print("debug.info", src(debug.info))
local function probe() return 1 end
print("probe", src(probe))
local chunk = [==[
local E = getfenv(1)
print("chunk env marker", E.busted)
return 42
]==]
local fn = loadstring(chunk, "=probe")
local env = setmetatable({busted={}}, {__index=_G})
setfenv(fn, env)
print("res", fn())