I have an OpenPGP key with an expired encryption-capable subkey, and a newer,
non-expired encryption-capable subkey.
if i get an encrypted message with an anonymous (all-zero) keyid subpacket in
the PSKESK, gpg 2.1.8 goes into try-all-secrets mode.
It first prompts me for a passphrase for my expired subkey, then for my
non-expired subkey.
It should default to trying the non-expired subkey first.