Essentially, when using the 'Import from Git' option under the '+Add' menu item against a private Gitlab project (i.e., OCP needs creds to do a `git pull`), the UI always says 'URL is valid but cannot be reached. If this is a private repository, enter a source Secret in advanced Git options' even when a valid secret is present and selected, and the BuildConfig that's generated will in fact successfully pull the repo upon clicking the 'Create' button at the bottom of the screen.

This same error message shows up even when the Gitlab repo is public too.

If the BuildConfig is edited after creation, the edit dialog reports the same error as well as complaining about not being able to determine the Git type:

The BuildConfig remains functional and working, but we've had multiple questions about this from customers using Gitlab internally.