[Software] GPG keeps private key despite deleting it

[Onsemeliot]

I created my key pair many years ago and everything works fine using Debian 12 so far. Recently I created a new key pair for an other computer (using my system) and exported the private and public key in order to use it elsewhere. (It works fine there too.) Afterwards I deleted the key pair on my primary system because I don't need the public key from the other system. Nevertheless, I want to write encrypted emails to the other system. Therefore, I imported only the public key to my keyring. Surprisingly, the secret key keeps returning as soon as I import the public key.
I have checked several times that I didn't mess up the export files. (I in fact did import the public key and not by accident the secret key.)
When I am searching for secret GPG keys on my system in the command line I can find the second private key (that shouldn't even be there) after importing the public key. But when I attempt to delete it GPG claims that it doesn't exist. (I can also find it using the Seahorse/Passwords app and when I delete it there using the GUI it looks like it is gone. Even on the command line it doesn't show up any longer.) But each time I import the public key the secret key magically returns too.
Do you have an Idea what I could do to get rid of the somewhat obscure hidden secret key on my system?

Code: Select all

$ gpg --list-secret-keys
/home/user/.gnupg/pubring.kbx
-------------------------------------
sec   rsa4096 2010-01-01 [SC]
      XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
uid           [ultimate] Name <name@mail.com>
ssb   rsa4096 2010-01-01 [E]

sec#  rsa4096 2020-01-01 [SC]
      YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
uid           [ultimate] Name2 <name2@mail.com>
ssb   rsa4096 2020-01-01 [E]

$ gpg --delete-secret-key YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
gpg (GnuPG) 2.2.40; Copyright (C) 2022 g10 Code GmbH
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

gpg: key "YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY" not found
gpg: YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY: delete key failed: Not found

[cds60601]

I think (and very well could be wrong) all you really need to do is revoke the key and create a new key-pair.

[Onsemeliot]

Thank you for your thoughts. But if I revoke the key I would need to replace it on the other system too. This would be a problem. Maybe I should instead just dump my whole key ring and create a new one. It seems you assume that this specific key is broken. I have to admit that I have encountered this behavior before. In this case I just did deal very cautiously and paid attention what I do. (I have created quite a few keys for coworkers because I usually set systems up for them.) It seems this is less related to this specific key but more a problem that occurs on my system. Maybe really my key ring is flawed.

[Onsemeliot]

I did some more testing. The problem really seems to be with this key. I generated two new private keys that do not share this issue. I can delete the private keys and when I import only the public keys they actually are only the public keys afterwards.