The chainhash import is challenging for consumers of the latest tagged btcd module (v0.22.0-beta) because that module revision has its own chainhash package. This creates an ambiguous import when trying to import both the older btcd module and btcec/v2 which requires the standalone module version of chainhash. This is the brute solution. An alternative would be to create a chaincfg/chainhash/v2 module and have btcec/v2 require that instead.