ods-enforcer crashes on seeing "key list --zone <zone> --verbose --keytag"

I am looking for a way to get the DS for a key in "waiting for ds-gone" state exported,
so that I can initiate action to have the correct now-obsolete DS record removed

from the DNS.  However, "key list --verbose --zone <zone>" only leaves me with cka_id and keytag to uniquely identify a given key.

However, "key export" does apparently not accept either "--cka_id"
or "--keytag" to identify the key to be exported.

"key export" has a "--keystate <state>" option, but that leaves me with the
unanswered question about how the different states are presented to the operator
and how "key export" expects its input as a value to the "--keystate" option.

So this turned me back to "key list" again.

However, doing

ods @ hugin: {37} ods-enforcer key list --zone 62.38.158.in-addr.arpa --verbose --keystate
Keys:
Zone:                           Keytype: State:    Date of next transition: Size: Algorithm: CKA_ID:                          Repository: KeyTag:
[Remote closed connection]
ods @ hugin: {38} 

leaves me with an error message and an ods-enforcer which has either crashed or exit()ed. This is quite serious in my judgement, and violates the most basic robustness principles, especially since the "--keystate" option is among the documented options for "key list".

Also, the question about how to get at the "--keystate" values is left unanswered.

Just for reference, when I omit the "--keystate" option, I get:

ods @ hugin: {41} ods-enforcer key list --zone 62.38.158.in-addr.arpa --verbose
Keys:
Zone:                           Keytype: State:    Date of next transition: Size: Algorithm: CKA_ID:                          Repository: KeyTag:
62.38.158.in-addr.arpa          KSK      retire    waiting for ds-gone      2048  8          22ec65fc0843188321b5ce68da186317 SoftHSM     2966
62.38.158.in-addr.arpa          ZSK      retire    ds-unsubmitted           1280  8          df0f2ec165e2e6a0338cd317412cd0a1 SoftHSM     3114
62.38.158.in-addr.arpa          ZSK      active    ds-unsubmitted           1280  8          f19e5f007a7da953e6b0d9f816415447 SoftHSM     53118
62.38.158.in-addr.arpa          KSK      active    ds-seen                  2048  8          465bba03e99cac2fb4a5bf9bb9331cc2 SoftHSM     34886
ods @ hugin: {42} 

which doesn't say anything about the values of "--keystate", and does not bring
me closer to being able to identify the now-obsolete DS key in the DNS.

"Help!"

Håvard