ReferenceError: AstSerializer is not defined

[tmcw]

Getting this error attempting to use webc:for. The culprit is pretty clear:

This line references AstSerializer but it isn't imported:

webc/src/looping.js

Line 55 in 8f10a7c

throw new Error(`Invalid ${AstSerializer.attrs.LOOP} attribute value: ${loopAttr}`);

Ideally this would be caught by a linter?

[11ty] Eleventy Fatal Error (CLI):
[11ty] 1. Having trouble writing to "./_site/index.html" from "./src/index.webc" (via EleventyTemplateError)
[11ty] 2. (./src/_includes/layouts/main.njk)
[11ty]   EleventyNunjucksError: Error with Nunjucks paired shortcode `renderTemplate` (via Template render error)
[11ty] 3. AstSerializer is not defined (via ReferenceError)