Tiny Crack Near Top of Skimmer Pot

My pump would not prime so I ran through the usual checks (lube the lid o-ring, empty skimmer basket, check the impeller, etc.). I finally found the source of my air leak to be a tiny crack near the top of the skimmer pot close to the lid. I "fixed" the issue short term by simply adding a little plumber's putty over that part of the pot. The pump primes everything runs normally.

I have a Pentair Challenger pump. The replacement pot is about $70 and I would probably pay for an hour or two of labor to have it installed professionally. Is there another way to fix this without replacing it? I'm wondering if there is some sort of rubber cement or something else that I can put over the small crack. I'm amazed at how such a tiny, hairline crack can let in enough air to lose prime!

Thanks in advance for any suggestions!