Comment 15 for bug 1754777

ok this seems to be caused by the tmp.mount unit, that is generated from /etc/fstab. Mounting a tmpfs over /tmp will make existing files inaccessible, so it has to be done as early as possible, i.e. `Before=basic.target`. It has to occur reliable before live-config.service invokes, so `WantedBy=live-config.service`. And the construct is activated by a symlink `/etc/systemd/system/live-config.service.wants/tmp.mount -> /etc/systemd/system/tmp.mount`.. that's my solution for now. : )