Package: lightdm Version: 1.18.2-2 While "dm-tool add-nested-seat" does work, it is not suitable for all uses, and "dm-tool add-seat" looks like the way to launch a real new X session.
However: * manpage mentions the syntax is "dm-tool add-seat TYPE" without giving any clue as to what TYPE should be * https://answers.launchpad.net/lightdm/+question/176458 and https://bbs.archlinux.org/viewtopic.php?id=185297 hint about "xlocal/xremote" as possible types * all TYPEs I tried resulted in this error: # dm-tool add-seat xlocal Unable to add seat: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: AddSeat is deprecated Looks like the message comes from lightdm itself! if (g_strcmp0 (method_name, "AddSeat") == 0) g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS, "AddSeat is deprecated"); else if (g_strcmp0 (method_name, "AddLocalXSeat") == 0) At least the manpage should tell it's not supposed to work anymore, and explain how to replace the feature. * switch-to-greater works, unless one wants to open a new session as a user already logged in * with add-local-x-seat we can get things to work with: I tried: # X :1 & # dm-tool add-local-x-seat 1 ... which does work, but with several inconveniences: * we have to find out by hand which tty was selected - I get tty2 or tty3 (despite a getty running there), instead of expected tty8, ie. the tty constraints obeyed by lightdm do not apply * dm-tool switch-to-user is of no use to discover this tty with several sessions for the same user
