$ headless-seo-check http://127.0.0.1:4311 --urls /shell,/cjk,/cjk-thin,/thin,/static --no-color
--- stdout+stderr ---
headless-seo-check: checking http://127.0.0.1:4311 …
headless-seo-check: 5 of 5 URLs selected, from --urls
headless-seo-check http://127.0.0.1:4311
  5 of 5 URLs checked, from --urls

  x /shell     static, 0 words
      warn  no canonical link in the served HTML
      error the served HTML carries 0 words — Googlebot has to run JavaScript to see this page
            7 <script src> + 3 KB inline JS + an empty root container
      warn  no links to any other page on this host — the navigation is not in the served HTML
  ! /cjk       static, 268 words
      warn  no canonical link in the served HTML
  x /cjk-thin  static, 39 words
      warn  no canonical link in the served HTML
      error the served HTML carries 39 words — Googlebot has to run JavaScript to see this page
            6 <script src> + 3 KB inline JS
      warn  no links to any other page on this host — the navigation is not in the served HTML
  ! /thin      static, 117 words
      warn  no canonical link in the served HTML
      warn  the served HTML carries 117 words for a page that ships an application bundle
            6 <script src> + 4 KB inline JS
  ! /static    static, 325 words
      warn  no canonical link in the served HTML

  FAILED  2 blocking issues, 8 warnings
     2 × empty-server-html

  What to do
    empty-server-html
      The server returns a shell — Googlebot has to execute JavaScript before it
      sees any content at all, and that rendering is queued, budgeted and never
      guaranteed. Move the content into the server render.

--- exit code: 1 ---