No, I'm generating an epub with Pandoc. It highlights code listings appropriately but it doesn't show line numbers in the code listings of the produced epub. Wondering if there's a way to do that.

Ah!  That's a bit clearer

I found a reference to the same issue and resolution for markdown <-> Latex <-> rst, but not epub.

https://github.com/jgm/pandoc/issues/763

He did say he didn't fix it in general.  But I didn't see any issues raised for that later.