I seem to continue having trouble with UpdateSearchIndexConfig.php, so I tried running it with the --startOver flag once. After this happened, I tried running UpdateSearchIndexConfig.php with and without this flag, and all I am getting now is this:
$ php /var/www/mediawiki/w/extensions/CirrusSearch/maintenance/UpdateSearchIndexConfig.php
And then the script finishes executing 0.1 seconds after this is printed out. What's the reason behind this early termination? I have errors turned on, so there isn't anything coming from.
Per what other people have done, I'm using Elasticsearch 6.8. (Please don't tell me to use 6.5.4, I've seen people using 6.8 and it works, I just don't know why it's so difficult to set it up on AWS Elasticsearch as opposed to a self-hosted solution.)