AWS Lambda : OpenBLAS WARNING - could not determine the L2 cache size on this system, assuming 256k - While using Google Custom Search API
This warning is just a warning, and has nothing to do with your problems.
BLAS is a highly optimised library, aiming to get near-perfect performance on all hardware. AWS Lambdas are supposed to run in a more abstract environment than most, and the low-level details of what CPU it's running on are not available to your code. Therefore OpenBLAS just guesses.
The only impact it would have is slightly reduced performance of certain mathematical operations, if the guess were incorrect.