Duplicates and MySQL access

Greetings,

I've been seeing duplicates in the KDE user group, kde.mail.kde.org. Just that 
one group. KMail doesn't see them as duplicates though.

Today I tried to run akonadiconsole to clear the akonadi cache, and got this 
error in a new window:

Failed to connect to database: Can't connect to local MySQL server through 
socket '/run/user/1000/akonadi/mysql.socket' (2) QMYSQL: Unable to connect

Of course I backed out hastily.

Everything else seems to be working just fine, so I'm at a loss to know what to 
try next. Any ideas?

-- 
Regards,
Peter.

Gentoo testing system, openrc-0.42.1
gcc 9.3.0, sys-kernel/gentoo-sources 5.7.3
QT 5.15.0, KDE frameworks 5.71.0, KDE plasma 5.19.1
KDE apps 20.04.2 incl KMail 5.14.1 (20.04.0), akonadi 20.04.1
dev-db/mariadb-10.4.12, net-libs/webkit-gtk-2.28.2
x11-drivers/xf86-video-amdgpu 19.1.0
dev-libs/amdgpu-pro-opencl-19.30.838629