OpenPGP card and secret keys

[Alex Mauer]

Werner Koch wrote:
> Okay, so it is not a communication problem with teh card.  Please run 
> 
>   gpg --debug 64 --clearsign test.txt
> 
> To see why gpg tries to use the primary key.

aha!  it does not.  It's trying to use a different subkey instead.
Surely missing secret key parts would be cause to reject that subkey as
a candidate for use, and just because secret parts are missing for one
subkey doesn't mean they're missing for all subkeys, right?

$ gpg --debug 64 --clearsign test.txt
gpg: DBG: finish_lookup: checking key 51192FF2 (all)(req_usage=0)
gpg: DBG:       using key 51192FF2
gpg: DBG: finish_lookup: checking key 51192FF2 (all)(req_usage=1)
gpg: DBG:       checking subkey 4A1C1224
gpg: DBG:       subkey looks fine
gpg: DBG:       checking subkey F4878DDE
gpg: DBG:       usage does not match: want=1 have=2
gpg: DBG:       checking subkey 9A37EEFF
gpg: DBG:       subkey looks fine
gpg: DBG:       using key 9A37EEFF
gpg: DBG: cache_user_id: already in cache
gpg: secret key parts are not available
gpg: no default secret key: general error
gpg: test.txt: clearsign failed: general error
secmem usage: 1408/3488 bytes in 2/15 blocks of pool 3488/32768