Self-adhering tape, foam-back tape, spare hanks, grommets,
shackles, pins, some small glue tubes, and a few strips of dacron with some pre-punched holes, in addition to the stuff you carry. That's for fixing a small rip or a chafe point. If it's a bigger issue, I usually carry an old sail (like a worn No. 3 used as a riding sail) that I could cut up if I was away from the sailmakers' for a couple of weeks.