I ran into an issue today where X is not working after and
upgrade of Stretch. The pervasive error
I am seeing is related to dbus-core. Xorg.0.log says ... Failed to connect to socket /var/run/dbus/system_bus_socket. Manual
attempts to navigate to that directory shows that /var/run exists, but
the dbus directory is not below 'run'. If I try to run startx it briefly brings up the initial screen but then X crashes and results in a command prompt environment again. I am also getting errors when trying to use apt, saying that no sources can be resolved. Seems like this latest round of updates really introduced some issues.