pycardano >=0.11 doesn't ship HDPublicKey — the v0.1 extraction
imported a symbol that never existed in the installed version, which
meant every address-derivation test failed at import time.
Use HDWallet rooted at the account level with public-only fields set,
then soft-derive receive chain (0) and staking chain (2). Hash the
resulting verification keys through PaymentVerificationKey /
StakeVerificationKey to compose the Shelley base address.
Refresh the test-vector xpub with a real, deterministic CIP-1852
account xpub derived from the well-known "test ... junk" mnemonic so
validate_xpub + derive_address actually exercise the BIP32 math.
Drop the "random hex should be rejected" assertion — BIP32-ED25519
soft derivation doesn't enforce that the 32-byte pubkey half is a
point on the curve, so arbitrary well-shaped hex is accepted by the
underlying crypto.
Kayos
eef22dc5cd