My standard repair kit. A light plastic tube to wrap a few meters of duct tape around. Inside the tube I put the safety pins and the piece of plastic foil containing needle and dental floss for sewing. A couple of meters of pretty soft wire is always part of the kit. The button... I do not know what for. It has been with me for a long time, and nowadays I do not even wear anything with buttons...
Conclusions and current insights: Most things made out of fabric can be fixed with either safety pins or needle and thread, plus some tape that covers it all. The wire is extremely strong and can be very useful. I have used it to splice a broken hiking pole that became so sturdy you could not tell it from the original.