[Bug] There is a block where all solution rewards are 0, which is unreasonable

[elderhammer]

🐛 Bug Report

ab1v24j6eqh75v3dgr3fwkgmv7zcun076gcdg8wz58y4c7w3pnufc9sfdahmc
https://aleo123.io/block/1231470

[raychu86]

Need to dig deeper and determine what changes are possibly needed, but here are some observations:

It looks like the reason there is 0 puzzle rewards in this block is due to how we are updating the coinbase targets.

If you look at block 1231469, you'll see that we've reached a cumulative_proof_target of 4296788923, which is less than the coinbase_target of block 1231468. However, due to the target adjustment algorithm, the new coinbase target for block 1231469 is less than the cumulative_proof_target.

This means that for block 1231470, our ratio of remaining rewards for that target is 0, thus the empty reward.

[randomsleep]

I submitted some bug reports about the PoW part at HackerOnce several days ago. I think this is a bug of incorrect updating coinbase_target, (report 2315260).