There are some issues here for packagers of Pantheon. The above patch on G-S-D constitutes a fork (of Canonical's fork) of 3.18.2, before plugins were initiated individually. Given the state of the xdg autostarts and gnome .session file in the sessions-settings package, it is apparent that this is not the version of G-S-D intended for it to be used with. Without any newer version publicised, the version to package for Pantheon on other distros is in limbo: the newer .session file is no longer compatible with the older G-S-D, the original manage-dpms-defaults patch is no longer compatible with newer versions of G-S-D.
I updated the patch to ship with 3.27.91-0ubuntu0~bionic1 (a prerelease version of what will ship with Ubuntu Bionic, and so theoretically elementary OS Juno), to package for ArchLinux.
This is what I have been spamming IRC about lately: https://github.com/elementary/default-settings/blob/42c817d531961e1ff74a8b899628121d7bf82f1e/dpms/elementary-dpms-helper#L19
The only source I am aware of for the
manage-dpms-defaults
key is this patched version of G-S-D: https://bazaar.launchpad.net/~elementary-os/elementaryos/os-patch-gnome-settings-daemon-xenial/revision/2There are some issues here for packagers of Pantheon. The above patch on G-S-D constitutes a fork (of Canonical's fork) of 3.18.2, before plugins were initiated individually. Given the state of the xdg autostarts and gnome .session file in the sessions-settings package, it is apparent that this is not the version of G-S-D intended for it to be used with. Without any newer version publicised, the version to package for Pantheon on other distros is in limbo: the newer .session file is no longer compatible with the older G-S-D, the original manage-dpms-defaults patch is no longer compatible with newer versions of G-S-D.
I updated the patch to ship with 3.27.91-0ubuntu0~bionic1 (a prerelease version of what will ship with Ubuntu Bionic, and so theoretically elementary OS Juno), to package for ArchLinux.