If you get Villager nobody of them traded Mending. That was after i spawn over 30 spawned Librarians in Creative and Survival (all with spawneggs), there were still nobody who traded mending...
Hope you fix.
MC-142801
No Mending with Villagers?!
Resolved
Cannot Reproduce
0
(Unassigned)
Unconfirmed
libarian, mending, server, village, villager-trade
Minecraft 19w03c
Retrieved
The enchantment is pretty rare. You just got unlucky. I can confirm mending villagers can still spawn