This morning as I finished airing up the tires on my bike, the little lock nut on my front-wheel Presta valve broke off the stem.
That means it will hold its pressure for now, the same as an undamaged valve, but as the tire gradually and inevitably loses pressure over the next few weeks, I'm not going to be able to re-inflate it. The next time it gets soft I'll have to replace the inner tube.
Not the end of the world, but what a pain. The last time this happened it was the night before Cycle Oregon.