Geas

I noticed that when you try to repair equipment, there is always a shortage on spools of thread. There are usually only 5 spools on sale, and they are needed for both cloth and leather armours.
Compared to spools of wire, which most often have 20 or more units for sale, and seem to be only used when repairing shields. No idea if it is a bug that metal armours and weapons can be repaired without the need to carry wire.

Anyways, considering the vast amount of leather and cloth armours, it would be more than welcomed if the respective shopkeepers could stock up a bit on their supply of spools of thread.

Not a bug as I remember , the shop stocks them 5 at a time but if they get bought 5 is the stock , if they arent bought the stock grows or it used to. Trick is to buy the stock when you see it and carry or store in your locker so that the shop replaces its stock often then you arent waiting when you have a huge collection of things for repair.

Or ...
pick hair from <dwarf>'s beard
!