Documented in more detail inline with the change.
LGTM. Nice and subtle.
Yes. This took us (mainly poor Edsko) days to track down.
Austin has told me off for not continuing the meme theme. So let me remedy that...
Applause to Edsko for several days hard work.
Closed by commit rGHC39630ab15cc0 (authored by @edsko, committed by @austin).