Currently, when there is a broken ID, it will not break any build until you build on Pantheon.

Example:

<code>
Running: ccutil deploy --target stage --lang en-US --doctype book --uuid 84f825c6-b193-470e-8731-62c8d4f39004
Transforming the AsciiDoc content to DocBook XML...
{{Unknown ID or title "proc-install-rhdh-ocp-operator_assembly-install-rhdh-ocp", used as an internal cross reference}}
{{Unknown ID or title "proc-install-operator_admin-rhdh", used as an internal cross reference}}
{{Unknown ID or title "proc-install-rhdh-ocp-helm_assembly-install-rhdh-ocp", used as an internal cross reference}}
{{Unknown ID or title "proc-install-rhdh-ocp-operator_assembly-install-rhdh-ocp", used as an internal cross reference}}
{{Unknown ID or title "proc-install-rhdh-ocp-helm_assembly-install-rhdh-ocp", used as an internal cross reference}}
{{Unknown ID or title "proc-install-rhdh-ocp-helm_assembly-install-rhdh-ocp", used as an internal cross reference}}
{{/var/lib/jenkins/workspace/doc-red_hat_developer_hub-1.2-administration_guide_for_red_hat_developer_hub-en-US (stage)/titles/admin-rhdh/build/en-US/master.xml fails to validate}}
Build step 'Execute shell' marked build as failure
</code>

In the PR builds on GitHub, we should test the documentation for broken xrefs.

One way to do it is to build with the ccutil container image quay.io/ivanhorvath/ccutil:amazing

Another way is to test the HTML for broken links.

cc: nickboldt