$card is a ProjectBoardTaskCard, which isn't a View, so you can't render it (it's just a structural object which represents a card, not an actual view of a card).

You can use getItem() to get a View (a PHUIObjectItemView) from it:

$view = $card->getItem();
$hovercard->appendChild($view);

With that change, I get this locally:

no it looks great

I think my high-quality local test data really bestows an aura of authority and authenticity upon it.

thanks for the test url reminder

Yeah, I had to dig it up myself. I'm not sure how to make it more obvious -- I guess we could put a little link or something on cards in development mode? Not sure how far down the path of "stuff is different in dev and production" we want to go.

I dropped the cover file for now. I want to figure out some treatment for the tags (and what workboards they are on, but looks like that wasn't abstracted out of Curtains, so I'll have to build that first.

ahahaha