In the beta version of the new Bing Webmaster Tools, Bing recently added a robots.txt tester. This is like the Google version but this quickly shows you the difference between the HTTP and HTTPS version of the URL.
Glenn Gabe I believe was the first to spot this and wrote on Twitter “Bing Webmaster Tools beta now has a nifty robots.txt Tester (like GSC). But also quickly enables you to see the https vs. http versions (which can be different).”
Here is a screen shot from Glenn:
You may be able to access at bing.com/webmasters/tools/robotstxttester – if not login first via www.aka.ms/newbwt and then navigate to it under the “Tools & Enhancements” section.
The help document on this feature says “BWT Robots.txt Tester helps Webmasters to analyze their robots.txt file and highlight the issues that would prevent them from getting optimally crawled by Bing and other robots.”
Forum discussion at Twitter.
Update: Yes, this is new:
