When we pull up Google Search Console, in the Index Coverage section, under the category of Excluded, there is a sub-category called ‘Duplicate page without canonical tag’.  The majority of the 665 pages in that section are from a test environment. If we were to include in the robots.txt file, a wildcard to cover every URL that started with the particular root URL ("www.domain.com/host/"), could we eliminate the majority of these errors? That solution is not one of the 5 or 6 recommended solutions that the Google Search Console Help section text suggests.  It seems like a simple effective solution.  Are we missing something?