我在data.lua文件里local item 添加 rail 不能用，mod报错。
Add the "rail" to the data file, not working.

你是想要添加铁轨吗?要添加相应物品的代吗?铁轨的源代码是:
{
type = "rail-planner",
name = "rail",
icon = "base/graphics/icons/rail.png",
icon_size = 64, icon_mipmaps = 4,
localised_name = {"item-name.rail"},
subgroup = "train-transport",
order = "a[train-system]-a[rail]",
place_result = "straight-rail",
stack_size = 100,
straight_rail = "straight-rail",
curved_rail = "curved-rail"
},

所以rail的type不是item,而是rail-planner.你可以在文件里添加一行:
data.raw["rail-planner"]["rail"].stack_size = 1000

非常感谢您！^-^
Thank you very much!