Astro is great once you get started. A bit funky if you have twenty years of legacy content.
Rather than do my usual — a screenshot and maybe a “lesson learned” post — this time around I made a public repo and public instance of this in-progress experiment available for your entertainment and edification.
Neither of which are still going four years later. Sorry about that. Had to tidy up some stuff. Astro changes quick enough that the repo would have done more harm than good at this point.
Oh and lesson learned: components are fussy, and the errors don’t always happen where you expect. Treat all your imported HTML as XHTML, and look for stray { characters. You might need to convert those to {.
Took me months to figure that out. Hopefully it saves you a few hours of confusion.