I have two daemons (game servers) started in screen sessions so that I may issue commands to the running servers. Occasionally one systemd services that start the servers will fail on boot with the error:

Cannot make directory '/run/screens': File exists

This seems to be because of a race condition in screen where both instances will try to create that directory on first run and if they both test that the directory doesn't exist yet, whoever tries to create it second fails. As a side note the directory seems to be created with the group of whatever user runs screen first which seems odd.

I've "solved" this (it's hard to tell by the nature of a race condition) by creating a file /etc/tmpfiles.d/screen.conf:

d /run/screens 0755 root root -

So that the directory exists prior to any screen session being run. You may want to consider shipping this as part of the package in /usr/lib/tmpfiles.d

Thanks.

Package: screen 4.3.1-2
Steps to reproduce: Try to execute two screen sessions as close to simultaneously as possible prior to /run/screens existing.