And I swear Yucca has poison tips - hurts more than just a sharp puncture
Assuming your pack isn't silnylon, then McNett Seam Grip is good. Polyurethane. Maybe put it on one side, let dry, then do other side.
Even after it dries, if you touch two places together they'll stick and ruin the patch. After it dries maybe 24 hours, you have to rub the surface with some powdery substance like talc, or dry clay dirt, or dry joint compound like spackle.
After you open it, that stuff dries out in the tube after a month or so, so don't get more than you need.