Populate Greeter process exit stderr
Summary:
Give more info in debug output when and how the Greeter porcess exited and
what counter-measures are triggered to unregular exits.
Should simplify debugging.
Reviewers: Plasma, apol
Reviewed By: apol
Subscribers: davidedmundson, zzag, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D28081