Render plugin breaks webc:setup function

[VAggrippino]

Operating system

Ubuntu 22.04

Eleventy

2.0.1

Describe the bug

Using Eleventy's built-in Render plugin breaks a function I defined in a webc:setup block, but only on the first build of the site. The error message doesn't even make sense. What could be the cause of this?

I have a component with a function to show a number of posts based on a dynamic attribute:
_components/collections-post.webc:

<script webc:setup>
    // Return the last n posts in reverse order
    const recent_posts = (n) => {
        const posts = collections.post
        const sorted = posts.sort((a, b) => a.page.date - b.page.date)
        const top = sorted.slice(0 - n)
        return top.reverse()
    }
</script>

<div class="h-feed">
    <article class="collections-post h-entry" webc:for="post of recent_posts(numposts)">
        <template @html="post.content" webc:nokeep></template>
    </article>
</div>

I use this on WebC pages like home.webc and blog.webc...

<collections-post @numposts="3"></collections-post>

I started using renderTemplate so that I could use a WebC component in my Markdown posts.

{% renderTemplate "webc" %}
    <rsvp
        answer="yes"
        url="https://example.com"
        event="Fun Event #20"
    ></rsvp>
{% endrenderTemplate %}

This worked when I first added renderTemplate and the <rsvp> component but, when I remove the output directory to rebuilt the entire site I get an error that doesn't make any sense...

[11ty] Problem writing Eleventy templates: (more in DEBUG output)
[11ty] 1. Having trouble rendering webc template ./_input/blog.webc (via TemplateContentRenderError)
[11ty] 2. Check the dynamic attribute: `webc:for="recent_posts(numposts)"`.
[11ty] Original error message: Cannot read properties of undefined (reading 'post') (via Error)
[11ty] 
[11ty] Original error stack trace: Error: Check the dynamic attribute: `webc:for="recent_posts(numposts)"`.
[11ty] Original error message: Cannot read properties of undefined (reading 'post')

It's saying that post is undefined, but that's in a webc:for block and it shouldn't even get to that line if post is undefined.

I checked the dynamic attribute (numposts) and it's set in any case. If I comment out the for loop and just show the number it'll build the site and show the number:

<div class="h-feed">
    <div @text="numposts"></div>
    <div webc:ignore>
    <article class="collections-post h-entry" webc:for="post of recent_posts(numposts)">
        <template @html="post.content" webc:nokeep></template>
    </article>
    </div>
</div>

Reproduction steps

1. Define a function in a webc:setup block that does something with a collection
2. Use {% renderTemplate "webc" %} in any Liquid / Markdown page.
3. Remove the output directory.
4. Rebuild the site: npx @11ty/eleventy
5. See an error

Expected behavior

It builds the site

Reproduction URL

No response

Screenshots

No response