Commit 72f2bb2 which attempted to clarify the interaction of aspect-ratio with grid item sizing introduced some errors in the most recent CR. This has been fixed in 72f2bb2
The resulting text is https://drafts.csswg.org/css-grid-1/#grid-item-sizing
Agenda+ to verify the resulting text and republish as CRD. CC @cbiesinger @Loirooriol