Parsing issue with a binding inside a bare <colgroup>

[rictic]

Writing this code:

  html` <colgroup> ${''} </colgroup> `

Yields an error of:

example-widget.ts:30:19 - error TS2322: false, This tag isn't closed.

30     return html` <colgroup> ${''} </colgroup> `;
                     ~~~~~~~~

Adding a tag before the colgroup resolves the issue, as does removing the binding. Maybe related to some of the weird parser rules around a <colgroup>, e.g. that it must live inside a <table> and it must not contain most normal content.