After a fruitless search for such a thing, I chanced upon this jacket in Decathlon.
It’s not a ‘cycling’ specific jacket, but I find it perfect. Excellent Autumn/Spring jacket; windproof and actually very water-resistant; I’ve been in proper downpours but haven’t got wet inside. Reasonably long at the back, and the sleeves are quite long, which is good if using a rucksack and stretching out on the bike.
In all, I’m very pleased with it. I find it a better fit than jackets costing over twice as much, and just as good quality. And it’s a darn sight more stylish than most ‘cycling’ kit, too.
There is a heavier ‘warm’ version, but that’s more a winter-weight jacket I’d say.