Comment 10 for bug 1777710

Here is the upstream bug report, which launchpad apparently does not recognize:

https://dev.gnupg.org/T3101

The workaround is to re-import only the public key, or in my case, I just did a --recv-keys to fetch it from keyserver.ubuntu.com and that pulled in the updated selfsig.

I understand that it now uses gpg-agent, but what I don't understand is why it bothers to do so just to import. It doesn't need to decrypt the key at that point; only copy it into the keyring.