Project local settings

Local settings can be configured by enabling the exrc option with set exrc in your init.vim and creating a .nvimrc file in the project's root directory. If neovim is launched in the same directory as .nvimrc, it will evaluate your user configuration first, followed by the local configuration. An example .nvimrc might be as follows

lua << EOF
  local nvim_lsp = require('lspconfig')

  nvim_lsp.rust_analyzer.setup {
    root_dir = function()
      return vim.fn.getcwd()
    end
  }
EOF

Be aware, after enabling exrc, neovim will execute any .nvimrc or .exrc owned by your user, including git clones.

If the only thing you care about configuring is the language server's settings, you might be able to use the on_init hook and the workspace/didChangeConfiguration notification:

local nvim_lsp = require('lspconfig')

nvim_lsp.rust_analyzer.setup {
  on_init = function(client)
    client.config.settings.xxx = "yyyy"
    client.notify("workspace/didChangeConfiguration")
    return true
  end
}