$ sudo /usr/bin/apt-key del 467B942D3A79BD29
$ sudo /usr/bin/apt-key del B7B3B788A8D3785C

$ sudo apt-key adv --keyserver pgp.mit.edu --recv-keys A8D3785C
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
Executing: /tmp/apt-key-gpghome.mimomkCxS8/gpg.1.sh --keyserver pgp.mit.edu --recv-keys B7B3B788A8D3785C
gpg: keyserver receive failed: No data

$ sudo gpg --homedir /tmp --no-default-keyring --keyring /usr/share/keyrings/mysql-apt-config.gpg --keyserver keyserver.ubuntu.com --recv-keys B7B3B788A8D3785C

# Add the repository to a `.list` file
echo "deb [signed-by=/usr/share/keyrings/mysql-apt-config.gpg] http://repo.mysql.com/apt/debian/ trixie mysql-8.4-lts" | sudo tee /etc/apt/sources.list.d/mysql.list > /dev/null

Hit:2 http://repo.mysql.com/apt/debian trixie InRelease
Err:2 http://repo.mysql.com/apt/debian trixie InRelease
  Sub-process /usr/bin/sqv returned an error code (1), error message is: Error: Failed to parse keyring 
"/usr/share/keyrings/mysql-apt-config.gpg"  Caused by:     0: Reading "/usr/share/keyrings/mysql-apt-config.gpg": EOF
     1: EOF

Quote

To generate keys suitable for use in APT using GnuPG, you will need to use the gpg --export-options export-minimal [--armor] --export command. Earlier solutions involving --keyring file --import no longer work with recent GnuPG versions as they use a new internal format ("GPG keybox database").

$ sudo gpg --homedir /tmp --no-default-keyring --no-permission-warning \
  --keyring gnupg-ring:/usr/share/keyrings/mysql-apt-config.gpg --keyserver keyserver.ubuntu.com \
  --recv-keys B7B3B788A8D3785C && sudo chmod +r /usr/share/keyrings/mysql-apt-config.gpg
gpg: key B7B3B788A8D3785C: "MySQL Release Engineering <mysql-build@oss.oracle.com>" 1 new signature
gpg: Total number processed: 1
gpg:         new signatures: 1

# install sq if not present:
$ test ! -x /usr/bin/sq && sudo apt-get -y install sq
$ sudo sq network keyserver --server hkps://keyserver.ubuntu.com search "B7B3B788A8D3785C" \
   --overwrite --output /usr/share/keyrings/mysql-apt-config.asc

Found 1 certificate related to the query:

 - BCA43417C3B485DD128EC6D4B7B3B788A8D3785C
   - MySQL Release Engineering <mysql-build@oss.oracle.com> (UNAUTHENTICATED)
   - created 2023-10-23 17:26:50 UTC
   - found via: hkps://keyserver.ubuntu.com

deb [signed-by=/usr/share/keyrings/mysql-apt-config.asc] http://repo.mysql.com/apt/debian/ trixie mysql-apt-config
deb [signed-by=/usr/share/keyrings/mysql-apt-config.asc] http://repo.mysql.com/apt/debian/ trixie mysql-8.4-lts
deb [signed-by=/usr/share/keyrings/mysql-apt-config.asc] http://repo.mysql.com/apt/debian/ trixie mysql-tools
# deb-src [signed-by=/usr/share/keyrings/mysql-apt-config.asc] http://repo.mysql.com/apt/debian/ trixie mysql-8.4-lts

$ sudo curl -fsSL -o /etc/apt/keyrings/mysql-archive.asc "https://keyserver.ubuntu.com/pks/lookup?op=get&options=mr&search=0xB7B3B788A8D3785C";

# update repo if needed:
$ echo "deb [signed-by=/etc/apt/keyrings/mysql-archive.asc] http://repo.mysql.com/apt/debian/ trixie mysql-8.4-lts" | sudo tee /etc/apt/sources.list.d/mysql.list > /dev/null

deb [signed-by=/usr/share/keyrings/mysql-apt-config.gpg] http://repo.mysql.com/apt/debian/ trixie mysql-8.0

# apt-get install mysql-community-client
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
E: Unable to locate package mysql-community-client

Types: deb deb-src
URIs:  http://repo.mysql.com/apt/debian/
Suites: trixie
Components: mysql-8.4-lts mysql-tools
Enabled: yes
Signed-By: /usr/share/keyrings/mysql-apt-config.gpg

WaylandGnome /home/igor # emerge --config dev-db/mysql


Configuring pkg...


 * Detected settings:
 * ==================
 * MySQL User:              mysql
 * MySQL Group:             mysql
 * MySQL DATA directory:        /var/lib/mysql
 * MySQL TMP directory:         /tmp
 * PID DIR:             /run/mysqld
 * Install db log:          /tmp/install_db.221119222.log
 * Install server log:          /tmp/install_mysqld.633921321.log
 * Trying to get password for mysql 'root' user from 'mysql' section ...
 * Trying to get password for mysql 'root' user from 'client' section ...

 * No password for mysql 'root' user was specified via environment
 * variable MYSQL_ROOT_PASSWORD and no password was found in config
 * file like '/root/.my.cnf'.
 * To continue please provide a password for the mysql 'root' user
 * now on console:
 * NOTE: Please avoid ["'\_%] characters in the password!
    >
 * Retype the password
    >

 * Initializing mysql data directory: /usr/sbin/mysqld --loose-skip-host-cache --loose-skip-name-resolve --loose-skip-networking --loose-skip-slave-start --loose-skip-federated --loose-skip-ssl --loose-skip-log-bin --loose-skip-relay-log --loose-skip-slow-query-log --loose-skip-external-locking --loose-skip-log-slave-updates --initialize-insecure --init-file='/tmp/tz.222211327.sql' --basedir='/usr' --datadir='/var/lib/mysql' --tmpdir='/tmp' --log-error='/tmp/install_db.221119222.log' --user=mysql
/var/tmp/portage/dev-db/mysql-5.7.41/temp/environment: line 3774: /tmp/install_db.221119222.log: Permission denied
 * ERROR: dev-db/mysql-5.7.41::gentoo failed (config phase):
 *   Failed to initialize mysql data directory. Please review '/tmp/install_db.221119222.log'!
 * 
 * Call stack:
 *     ebuild.sh, line 136:  Called pkg_config
 *   environment, line 3777:  Called die
 * The specific snippet of code:
 *           die "Failed to initialize ${PN} data directory. Please review '${mysql_install_log}'!";
 * 
 * If you need support, post the output of `emerge --info '=dev-db/mysql-5.7.41::gentoo'`,
 * the complete build log and the output of `emerge -pqv '=dev-db/mysql-5.7.41::gentoo'`.
 * The complete build log is located at '/var/tmp/portage/dev-db/mysql-5.7.41/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/dev-db/mysql-5.7.41/temp/environment'.
 * Working directory: '/var/tmp/portage/dev-db/mysql-5.7.41/empty'
 * S: '/var/tmp/portage/dev-db/mysql-5.7.41/work/mysql-5.7.41'

WaylandGnome /home/igor # ls -la /tmp/ins*
-rw-r--r-- 1 mysql root 0 Jul 16 21:10 /tmp/install_db.221119222.log
-rw-r--r-- 1 mysql root 0 Jul 16 21:10 /tmp/install_mysqld.633921321.log
WaylandGnome /home/igor #

WaylandGnome /home/igor # ls -la /
total 202248
drwxr-xr-x  21 root root      4096 Aug 21  2021 .
drwxr-xr-x  21 root root      4096 Aug 21  2021 ..
drwxr-xr-x   2 root root      4096 Apr  3  2024 bin
drwxr-xr-x   3 root root      4096 Jun 16  2024 boot
drwxr-xr-x  16 root root      3580 Jul 16 21:07 dev
drwxr-xr-x  79 root root      4096 Jul 16 21:07 etc
drwxr-xr-x   3 root root      4096 Aug 16  2021 home
drwxr-xr-x  12 root root      4096 Jun 24  2024 lib
drwxr-xr-x   6 root root      4096 Dec  8  2024 lib64
drwx------   2 root root     16384 Aug  9  2021 lost+found
drwxr-xr-x   2 root root      4096 Aug  8  2021 media
drwxr-xr-x   4 root root      4096 Aug 29  2021 mnt
-rw-r--r--   1 root root      9865 Aug 21  2021 modules_loaded
drwxr-xr-x   2 root root      4096 Aug  8  2021 opt
dr-xr-xr-x 243 root root         0 Jul 16 16:07 proc
drwx------   6 root root      4096 Jul 16 21:10 root
drwxr-xr-x  20 root root       680 Jul 16 21:08 run
drwxr-xr-x   2 root root      4096 Jun 24  2024 sbin
-rw-r--r--   1 root root 207004312 Aug  9  2021 stage3-amd64-openrc-20210808T170546Z.tar.xz
dr-xr-xr-x  13 root root         0 Jul 16 16:07 sys
drwxrwxrwt  10 root root      4096 Jul 16 21:10 tmp
drwxr-xr-x  12 root root      4096 Aug  8  2021 usr
drwxr-xr-x  10 root root      4096 Dec  8  2024 var
WaylandGnome /home/igor #