VVE-2021-0002: Incorrect `returndatasize` when using simple forwarder proxies deployed prior to EIP-1167 adoption

Background @tjayrush reported a data handling issue with certain Web3 libraries using Vyper-deploy forwarder proxy contracts using our Vyper's built-in createforwarderto function prior to our change to support EIP-1167 style forwarder proxies. Impact If you are an end user of a forwarder-style...