There was discussion on Twitter today (https://twitter.com/PttPrgrmmr/status/1132351142938185728) about how the Bash manual appears to not be indexable by search engines.
https://www.gnu.org/software/bash/manual/bashref.html redirects to https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html, and www.gnu.org/robots.txt has "Disallow: /savannah-checkouts/" We reasoned that this probably wasn't deliberate and wanted to report it.