Wikimedia Bugzilla is closed!

If the parsoid service is down (`sudo service parsoid stop`, or update extension/Parsoid and forget/fail `npm install`), then viewing flow pages fails with exception

   Parser only supports wikitext to HTML conversion

   Backtrace:

   #0 /srv/mediawiki/extensions/Flow/includes/ParsoidUtils.php(24): Flow\ParsoidUtils::parser('html', 'wikitext', '<p>It's a long ...')

This is true, but it masks the real problem that parsoid has to work, and didn't.  ParsoidUtils::convert has a try-catch block around using parsoid, and if that fails it will fall back to using parser. It would be helpful for wiki operators if the exception message included the parsoid failure, e.g.
   Parser only supports wikitext to HTML conversion (and parsoid earlier failed with exception "VisualEditor is unavailable")

Now that I've figured out what's going on, this has become a low-priority bug :-)