Assertion in Document_symbols.compute is triggered #16

I have been working on a Visual Studio Code language client for Forester, and it is actually triggering this assertion:

let compute ({textDocument = {uri; _}; _} : L.DocumentSymbolParams.t) :
    [> `DocumentSymbol of L.DocumentSymbol.t list] option =
  let Lsp_state.{forest; _} = Lsp_state.get () in
  let uri = URI.of_lsp_uri ~base:forest.config.url uri in
  match State.get_code ~forest uri with
  | None -> assert false

It was extremely difficult to detect that this was happening, because I don't yet have a good way to debug forester while the language server is running.