Realisticly, what DO you fix it with? Remember, you're in a big can. One person farts, and everybody knows who did it, and hates them. You've got to live with whatever outgasses from the goop you put on the crack for a LONG time! So, no silicone RTV (acetic acid), no epoxy (urea), no CA glues (toxic/noxious vapor), basically, no solvent-based glue or adhesive. No catalyst-cured glue or adhesive that outgasses. Bubble gum might work; it seals the crack, stays (fairly) flexible at room temp, and will freeze solid in cold or zero pressure. Just make sure it's not Juicy Fruit, or cinnamon, or clove, or...