During installation, prompt the following content:
To be clear, "GNU diff3 not found" means users may get the "Edit conflict" screen more often because MediaWiki will be unable to merge otherwise non-conflicting edits automatically. This could be a big deal on a busy wiki. MediaWiki should still be able to compare revisions in the page history though.
In contrast, "Git version control software not found" merely means that commit dates (though not commit hashes) will be missing from Special:Version, if you have installed MediaWiki or MediaWiki extensions using Git. You can still look up the dates manually by following the links to git.wikimedia.org, or by using git yourself.
I found that diff3 and git have been installed, but the installation prompt was not found.
