I was getting this error on Ubuntu 20.04 LTS with MySQL version 8.0.35.
Err:1 http://repo.mysql.com/apt/ubuntu focal InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B7B3B788A8D3785C
After some research, I tried several suggestions that I found at the links below, but they did not resolve the issue.
https://askubuntu.com/questions/1497140/how-to-fix-apt-update-after-to-upgrade-the-mysql-list-file
https://www.reddit.com/r/mysql/comments/18jj4hm/terminal_update_error/
https://askubuntu.com/questions/1389928/mysql-an-error-occurred-during-the-signature-verification
https://github.com/apache/airflow/issues/20911
However, finally came across this link which did have a solution:
https://askubuntu.com/questions/1498081/no-pubkey-and-some-of-the-file-has-an-unsupported-filetype
Below are the steps to quickly fix it:
- Download an updated .deb file from the official mysql site:
https://dev.mysql.com/downloads/repo/apt/ - Install the deb (e.g., mysql-apt-config_0.8.29-1_all.deb):
sudo dpkg -i <filename> - Then run apt-get update again and the error should not appear.