Error when the background is null

[perrin4869]

I just upgraded to the latest HEAD where lush is removed and ran require('nvim-treeclimber').setup(). This results in an error:

Error detected while processing /home/perrin4869/dotfiles/home/.config/nvim/plugin/treeclimber.lua:
E5113: Error while calling lua chunk: ...fault/start/nvim-treeclimber/lua/nvim-treeclimber/hi.lua:18: bad argument #2 to 'hex' (number expected, got nil)
stack traceback:
        [C]: in function 'hex'
        ...fault/start/nvim-treeclimber/lua/nvim-treeclimber/hi.lua:18: in function 'bg_hsluv'
        .../default/start/nvim-treeclimber/lua/nvim-treeclimber.lua:12: in function 'setup'
        ...in4869/dotfiles/home/.config/nvim/plugin/treeclimber.lua:1: in main chunk

The root cause is that I have this inside my vimrc: hi Normal guibg=NONE, which results in vim.api.nvim_get_hl_by_name("Normal", true) returning:

{
  foreground = 15457202
}

I think maybe there should be a case handling for background = null?

[Dkendal]

Thanks for the report, I'll take a look this week!