How to disable interception of errors by Ingress in a Tectonic kubernetes setup
I have solved this on Tectonic 1.7.9-tectonic.4.
In the Tectonic web UI, go to Workloads -> Config Maps and filter by namespace tectonic-system.
In the config maps shown, you should see one named "tectonic-custom-error".
Open it and go to the YAML editor.
In the data field you should have an entry like this:
custom-http-errors: '404, 500, 502, 503'
which configures which HTTP responses will be captured and be shown with the custom Tectonic error page.
If you don't want some of those, just remove them, or clear them all.
It should take effect as soon as you save the updated config map.
Of course, you could to the same from the command line with kubectl edit:
$> kubectl edit cm tectonic-custom-error --namespace=tectonic-system
Hope this helps :)