Here are three identical searches on Google, DuckDuckGo, and Bing:
searching "MAKEFILE_LIST" site:www.gnu.org/software/make on google
searching "MAKEFILE_LIST" site:www.gnu.org/software/make on duckduckgo
searching "MAKEFILE_LIST" site:www.gnu.org/software/make on bing
Note how DuckDuckGo and even Bing find the correct answer, whereas Google responds with "what? IDK, nothing to see here".
It's been known that Google search has been "getting worse and worse" in general as the result of slowly losing the war against SEO spam, but this isn't even that. This is Google just flat-out shutting off useful functionality because $REASONS, I guess.
If I still had solid social-media ties with people working at Google I'd ask them to query WTF internally, but the vast majority of those ties were severed when Google+ shut down and most of the rest are to people who were working there when I worked there a decade ago but don't work there any more.
