sudo apt update
…
Err:9 http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_18.04 InRelease
The following signatures were invalid: EXPKEYSIG 4ABE1AC7557BEFF9 isv:ownCloud OBS Project isv:ownCloud@build.opensuse.org
…
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_18.04 InRelease: The following signatures were invalid: EXPKEYSIG 4ABE1AC7557BEFF9 isv:ownCloud OBS Project isv:ownCloud@build.opensuse.org
W: Failed to fetch http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_18.04/InRelease The following signatures were invalid: EXPKEYSIG 4ABE1AC7557BEFF9 isv:ownCloud OBS Project isv:ownCloud@build.opensuse.org
W: Some index files failed to download. They have been ignored, or old ones used instead.
I tried some “magic fu” from other Google results:
wget -qO - http://download.owncloud.org/download/repositories/stable/Ubuntu_18.04/Release.key | sudo apt-key add -
But that made no difference.
sudo apt-key list
…
pub rsa2048 2016-09-25 [SC] [expired: 2020-01-18]
1B07 204C D71B 690D 409F 57D2 4ABE 1AC7 557B EFF9
uid [ expired] isv:ownCloud OBS Project isv:ownCloud@build.opensuse.org
…
Maybe this expired key is the problem?
What is the correct “magic fu” to fetch a new key from soemwhere?