This bug was fixed in the package sddm - 0.17.0-1ubuntu4
--------------- sddm (0.17.0-1ubuntu4) bionic; urgency=high
* Fix race between sddm and logind (LP: #1763977).
-- Simon Quigley <email address hidden> Sun, 15 Apr 2018 14:36:43 -0500
This bug was fixed in the package sddm - 0.17.0-1ubuntu4
---------------
sddm (0.17.0-1ubuntu4) bionic; urgency=high
* Fix race between sddm and logind (LP: #1763977).
-- Simon Quigley <email address hidden> Sun, 15 Apr 2018 14:36:43 -0500