`(require 'tui)` fails

[ieure]

Hi, I saw your EmacsConf talk on tui.el and thought I'd give it a whirl, as I'm trying to build more interactive tooling on Emacs.

Based on the README, I eval'd this code:

(straight-use-package
 '(tui :type git :host github :repo "ebpa/tui.el" :files ("*.el" "components" "layout" "demo" "snippets")))

(require 'tui)

The require fails with an error:

Debugger entered--Lisp error: (void-variable tui-element-outline)
  byte-code("\302\10\301 \303\304\11!$\207" [tui-element-outline element tui-defun "Structure outline of ELEMENT and its children." tui-element-outline-string] 6)
  require(tui-dev)
  load-with-code-conversion("/home/ieure/.emacs.d/straight/build/tui/tui.el" "/home/ieure/.emacs.d/straight/build/tui/tui.el" nil t)
  require(tui)
  pp-eval-expression((require 'tui))
  pp-eval-last-sexp(nil)
  funcall-interactively(pp-eval-last-sexp nil)
  command-execute(pp-eval-last-sexp)

I assume this isn't expected behavior. Is the README current?