local err = ...;
local i = 2;

io.stderr:write("unhandled error: ", tostring(err), "\n");

while true do
	local info = debug.getinfo(i, "Snl");
	if info == nil then break end

	local name = info.name;
	local location = info.short_src;

	if location == "[C]" then
		location = "at <C>";
	elseif location:find "%[string" then
		location = "at <string>";
	else
		location = "at " .. location;
	end

	if info.currentline > 0 then
		location = location .. ":" .. info.currentline;
	end

	if name ~= nil then
		io.stderr:write("  ", location, " in ", name, "\n");
	else
		io.stderr:write("  ", location, "\n");
	end

	i = i + 1;
end

return err;