How do you set terminal options like t_Co in neovim?

Question

When I put into my ~/.config/nvim/init.lua

vim.opt.t_Co = 256

I get

E5113: Error while calling lua chunk: vim/_meta.lua:659: Not a valid option name: t_Co

But there is an option in vim called t_Co. This is a port from my vimrc line,

set t_Co=256

Answer 1

Regardless of the configuration file format these are a no-op in VIM Script and an error in the Lua API. From :he t_xx

t_xx termcap-options t_AB t_Sb t_vb t_SI Nvim does not have special t_XX options nor <t_XX> keycodes to configure terminal capabilities. Instead Nvim treats the terminal as any other UI, e.g. guicursor sets the terminal cursor style if possible.