Difficulty setting up CI in 8.0 from scratch

I enabled CI in the config file as described here. Then, I ran sudo gitlab-ctl reconfigure as required. The process failed because there was no gitlab-ci user on the system:

Recipe: gitlab::gitlab-ci_disable
  * directory[/var/opt/gitlab/ci-backups] action create
    * cannot determine user id for 'gitlab-ci', does the user exist on this system?

I added this user manually as follows:

sudo adduser --disabled-login --gecos 'GitLab CI' gitlab-ci

Then, I got another error about a missing rc file:

STDOUT: /opt/gitlab/bin/gitlab-ci-rake error: could not load /opt/gitlab/etc/gitlab-ci/gitlab-ci-rc
    Either you are not allowed to read the file, or it does not exist yet.
    You can generate it with:   sudo gitlab-ctl reconfigure

Running sudo gitlab-ctl reconfigure again fixed this, though there should be a way for this file to be created without running reconfigure multiple times.

I had to leave this option checked, which seemed very odd given the explanatory text:

Then I was able to enable CI for my projects and add runners.