I have my files already downloaded and am volume mounting them inside a docker container. When I run headless (or even the GUI version via VNC) I see the “parent is missing” error and nothing syncs.
The issue was locale settings. I switched the container from debian --> ubuntu and simply did the following:
apt-get install language-pack-en
ENV LC_ALL en_US.UTF8
ENV LANG en_US.UTF8
And everything worked (after a while of index building/etc). Thanks @lpugoy