process frontmatter for dynamic permalinks including the tag-names using WebC

[johannesrave]

Operating system

Ubuntu 23.04

Eleventy

2.01

Describe the bug

I'm trying to generate index-pages for my tags using pagination, pretty much following the Quick Tip from the documentation, except for the fact I recently ported my page to WebC instead of Liquid. However, I cannot figure out how to format the permalinks to generate the pages based on the tag-names, which in Liquid would've been done like so:

---
pagination:
  data: collections
  size: 1
  alias: tag
  filter: [all]
permalink: "tags/{{ tag }}/"
---

Using several permutations of guessing how to writr this in WebC, template-strings and javascript-style-frontmatter, I'm always getting something to the tune of

Eleventy:EleventyErrorHandler (error stack): DuplicatePermalinkOutputError: Output conflict: multiple input files are writing to `public/tags/{{ tag }}/index.html`. Use distinct `permalink` values to resolve this conflict.
  Eleventy:EleventyErrorHandler   1. ./blog/tags/pagination.webc
  Eleventy:EleventyErrorHandler   2. ./blog/tags/pagination.webc
  Eleventy:EleventyErrorHandler   3. ./blog/tags/pagination.webc

I'm more confused by the fact that in another WebC-template, the double-curly format to generate my posts at date-based urls appears to be working fine:

---
layout: "_layouts/document.webc"
title: my title
permalink: "posts/{{ page.date | date: '%Y' }}/{{ page.date | date: '%m' }}/{{ page.date | date: '%d' }}/{{ title | slugify }}"
tags: post
---

is it because there are filters involved? I've spent several hours on this and am now stumped and feel stupid, would be thankful for a pointer or a workaround.

Reproduction steps

generate pages with dynamic permalinks including the tag-names using the pagination feature in a WebC-template

Expected behavior

pages are generated like

/tags/personal/index.html
/tags/til/index.html
...

Reproduction URL

No response

Screenshots

No response

[johannesrave]

update:
i found the issues pertaining to the exact formatting of the permalink with webc in https://github.com/11ty/eleventy-plugin-webc, so sorry for posting here.

the relevant (resolved) issues were namely 11ty/eleventy-plugin-webc#27 and 11ty/eleventy-plugin-webc#36.

from those threads i learned that i have to format it like permalink: "'/tags/' + tag + '/'" (the difference to what i tried before being that nested quotes i think, as if eval-ing the string).

unfortunately, i ran into 11ty/eleventy-plugin-webc#87 right after.

i'm also still hazy on why the liquid-style double curlies work in the other case illustrated in my original post, as that is also inside a .webc-file.