This puncture is on the inside face of the tube. One day I got a big piece of glass in my tire. I patched it up and then I got a puncture on the inside face of the tube. I patched that and then I got another puncture on the inside within a few blocks. I patched that and then I got a third puncture on the inside within another few blocks. The punctures are not in the same place so I'm pretty sure the rim is not the issue. Do I have a piece of glass inside the tube, rolling around and puncturing in random places? Why are the holes only on the inside face of the tube? Will any new tube fall to the same fate?
It looks like a glass cut to me.
It is common for glass to lurk in the tire case, so this is unusual.
Take the tire and tube off completely and inspect the inside of the rim and the tire carefully. If you can't see anything, run your fingers around the rim and the tire.
If you still haven't found anything, take the rim tape off and check it and the rim again.
If you still haven't found anything, reassemble, sigh deeply, and hope for the best.
If you didn't already, you need to clear the inside of the tire of whatever debris is causing the flat, before replacing the tube. From your description, it sounds like the culprit that is causing the problem hasn't been cleared from the inside of the tire, so you may continue to get flats over and over. At this point, I'd replace the tube at least, and possibly the tire as well. Next time you need to replace a tube, make sure to slowly and carefully examine the inside of the tire with your fingers (being careful not to get any glass or splinters in yourself). If you can't identify what's causing the flat from that, hold off on replacing the tube, because it will probably happen again, or, take it to a shop.
The other possibility is that you're not installing the tube properly and it's pinching when you inflate, causing a pinch flat. Make sure everything is seated properly and that no section of the tube is bulging out of the tire before inflation.
This puncture made from outside - the glass isn't inside the tube, but did you get it out of the tire? Is your tire intact? Did you hear the tube blowing up?
It looks like your tire have something that punctures the tube. It maybe a glass in it, or metal hoop that inside tire bead came out, or the tire sniped in some place. As every time when you install the tube you rotate the tire, the puncture will be at another place on the tube.
I have had the same baffling issue lately, and I still don't have a positive identification of the cause for the puncture: I just got the second puncture on the inside (toward the spokes) of the tube. I have adhesive-backed cloth rim tape, so I'm sure that's not moving; I installed the tube by hand, and I'm certain it wasn't kinked or nicked by a screw-driver, etc. There was absolutely nothing in the tread or in the inside of the tire.
Two factors were common on both days I experience this kind of flat. I had just topped up the air pressure to 90 psi, and the day was hot (I live in Texas). Today, I rode 17 miles to work on the tire in the morning with no problem. Less than a quarter mile into the ride home in the afternoon, the tire went flat. It was similar the last time, too. I have to assume that getting out on very hot pavement (the asphalt was soft and melting in places) caused the tire pressure to increase. I'm not sure of the physics, but it's possible that that this would cause the tube to develop a hole in that location.
I think the solution in my case is to keep the tires inflated to a lower pressure (as measured cold by the tire gauge) when it's this hot out because the pavement is going to heat them up and increase the pressure.