Guess this is just a --localstatedir=/var option that should be passed to configure.

# Default values are shown for each setting, it's not required to uncomment
# any of the lines. Exception to this are paths, they're just examples with
# the real defaults being based on configure options. The paths listed here
# are for configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
# --with-ssldir=/etc/ssl

# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/

...
##
## Login processes
##

# <doc/wiki/LoginProcess.txt>

# Directory where authentication process places authentication UNIX sockets
# which login needs to be able to connect to. The sockets are created when
# running as root, so you don't have to worry about permissions. Note that
# everything in this directory is deleted when Dovecot is started.
#login_dir = /var/run/dovecot/login

# chroot login process to the login_dir. Only reason not to do this is if you
# wish to run the whole Dovecot without roots. <doc/wiki/Rootless.txt>
#login_chroot = yes

# User to use for the login process. Create a completely new user for this,
# and don't use it anywhere else. The user must also belong to a group where
# only it has access, it's used to control access for authentication process.
# Note that this user is NOT used to access mails. <doc/wiki/UserIds.txt>
#login_user = dovecot


Have you set anything different?


I haven't noticed anything here in everything.log. But when you can confirm this we can add --localstatedir=/var to make sure for future updates it's fixed.

No, I haven't changed that setting. I only got the message once, it hasn't happened since. My /usr/var/run/dovecot/ does contain files from dovecot processes with update times matching daemon start time, however.