Invalid character in entity name

[seetee]

Describe the bug
Osmosfeed has been running fine for about a month. Suddenly the build action started to fail. It seems one feed in particular causes the error. The feed is news from Sweden’s leading magazine about astronomy and space travel.

The error identifies as "Invalid character in entity name".

Could this be a UTF-8 thing?

Bug area (choose one)

• Site builder: anything broken in the GitHub action
• Reader UI: anything broken while you are reading the feed

To reproduce the bug
Run the build action with the news feed from "Populär Astronomi".
https://www.popularastronomi.se/feed/

##[debug]Evaluating condition for step: 'Build the feed'
##[debug]Evaluating: success()
##[debug]Evaluating success:
##[debug]=> true
##[debug]Result: true
##[debug]Starting: Build the feed
##[debug]Loading inputs
##[debug]Loading env
Run npm run build
##[debug]/usr/bin/bash -e /home/runner/work/_temp/5cea[2](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:2)847-7787-4ace-890e-e8f5ba0b1[3](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:3)3e.sh

> osmosfeed-template@1.0.0 build
> osmosfeed

[main] Starting build using cli version 1.15.1
[system-file] Config: /home/runner/work/osmosfeed/osmosfeed/osmosfeed.yaml
[system-file] Local cache: undefined
[system-file] Template: /home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/system-templates/index.hbs
[system-file] System static: /home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/system-static/favicon.ico
[system-file] System template static: /home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/system-static/index.css
[system-file] System template static: /home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/system-static/index.js
[load-config] Effective config:  {
  sources: [
    { href: 'https://github.com/osmoscraft/osmosfeed/releases.atom' },
    { href: 'https://inkscape.org/news/feed/' },
    { href: 'https://www.scribus.net/feed/' },
    { href: 'https://www.drupal.org/planet/rss.xml' },
    { href: 'https://www.drupal.org/section-blog/all/feed' },
    { href: 'https://www.smashingmagazine.com/feed/' },
    { href: 'https://developer.mozilla.org/en-US/blog/rss.xml' },
    {
      href: 'https://www.d.umn.edu/itss/training/online/webdesign/webdesign.xml'
    },
    { href: 'https://www.kryogenix.org/days/feed' },
    { href: 'http://www.thelins.se/johan/blog/feed/' },
    { href: 'https://feeds.feedburner.com/TroyHunt' },
    { href: 'https://rythian.tumblr.com/rss' },
    { href: 'https://www.helahisingen.se/feed/' },
    { href: 'https://nyhetersto.se/feed/' },
    { href: 'https://api.sr.se/rss/channel?id=10[4](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:4)' },
    { href: 'https://api.sr.se/api/rss/program/83' },
    { href: 'https://www.gp.se/nyheter/g%C3%B6teborg?rss' },
    { href: 'https://noyb.eu/en/rss' },
    { href: 'https://www.popularastronomi.se/feed/' },
    { href: 'https://status.mangadex.org/history.rss' },
    { href: 'https://www.driftbloggen.se/feed/' }
  ],
  cacheUrl: 'https://seetee.github.io/osmosfeed/cache.json',
  cacheMaxDays: 30,
  siteTitle: 'osmos::feed',
  timezone: null,
  timezoneOffset: 0,
  githubServerUrl: 'https://github.com',
  githubRepository: 'seetee/osmosfeed',
  githubRunId: '6444377118'
}
[get-cache] Use remote cache: https://seetee.github.io/osmosfeed/cache.json
[discover-cache] Pre-build cache restored: https://seetee.github.io/osmosfeed/cache.json
[enrich] 0.91s |  14 cached | -11 new | https://www.d.umn.edu/itss/training/online/webdesign/webdesign.xml
[enrich] 2.86s |   0 cached |   0 new | https://github.com/osmoscraft/osmosfeed/releases.atom
[enrich] 3.18s |   6 cached |   0 new | https://www.driftbloggen.se/feed/
[enrich] 3.32s | 132 cached |  -[5](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:5) new | https://www.drupal.org/planet/rss.xml
[enrich] 3.34s |   [6](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:6) cached |   1 new | https://www.drupal.org/section-blog/all/feed
[enrich] Parse source failed https://www.popularastronomi.se/feed/
/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:184[7](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:7)[8](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:8)
        er = new Error(er);
             ^

Error: Invalid character in entity name
Line: 0
Column: 2028
Char: @
    at error (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:18478:14)
    at strictFail (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:18501:11)
    at SAXParser.write (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:1[9](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:9)209:17)
    at Parser4.parseString (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:25475:35)
    at Parser4.parseString (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:25[15](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:16)5:21)
    at /home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:26035:26
    at new Promise (<anonymous>)
    at Parser4.parseString (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:26034:[20](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:21))
    at enrichInternal (/home/runner/work/osmosfeed/osmosfeed/node_modules/@osmoscraft/osmosfeed/bin/main.js:4[26](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:27)04:[32](https://github.com/seetee/osmosfeed/actions/runs/6444377118/job/17500138579#step:5:33))
    at runMicrotasks (<anonymous>)
Error: Process completed with exit code 1.
##[debug]Finishing: Build the feed