> whereas Gruyère has no holes

TIL that Gruyere from France is different to Swiss and it must have holes.

https://en.wikipedia.org/wiki/Gruy%C3%A8re_cheese > The PGI documentation also requires that French Gruyère has holes "ranging in size from that of a pea to a cherry", a significant departure from the Swiss original. Peter Ungphakorn, a Swiss local and an international trade expert, comments that the French Comté cheese could be a closer match to the Swiss version.

And there is a good image of Gruyere with holes here, https://classicfinefoods.co.uk/dairy/5713-french-gruyere-pgi...