After updating to openpgp-ca 0.12.0, I got this: ``` + oca wkd export wkd Error: No binding signature at time 2023-02-14T10:16:07Z Caused by: 0: Policy rejected non-revocation signature (PositiveCertification) requiring second pre-image resistance 1: SHA1 is not considered secure since 2023-02-01T00:00:00Z ``` 1. For users this error message should contain more data, to be helpful. Show which key is problematic. Maybe give some hints on how to move forward. 2. If the problem is only with one key, then show it as a warning, continue exporting valid keys to wkd.