Looks like a heavy bug and this is an important compiler... how many other unknown bugs are out there? And how much will this one impact DeFi, as there are a lot of vyper contracts out there 😱
PSA: Vyper versions 0.2.15, 0.2.16 and 0.3.0 are vulnerable to malfunctioning reentrancy locks. The investigation is ongoing but any project relying on these versions should immediately reach out to us.