While Better-Diffs-2023 is ongoing, it might be useful to expose the version of wikidiff2 (when available) in the "Installed software" section of Special:Version.
See https://commtech.wmcloud.org/wiki/Special:Version#mw-version-software, and the below hacky snippet, for an example:
diff --git a/includes/specials/SpecialVersion.php b/includes/specials/SpecialVersion.php index 3c929c5201..b3163210db 100644 --- a/includes/specials/SpecialVersion.php +++ b/includes/specials/SpecialVersion.php @@ -330,19 +330,12 @@ class SpecialVersion extends SpecialPage { private function getSoftwareInformation() { $dbr = wfGetDB( DB_REPLICA ); - // HACK - // Don't even... --TheresNoTime - $wd2path = '/var/www/wikidiff2'; - $wd2mod = date("Y-m-d H:i:s", filectime("/usr/lib/php/20210902/wikidiff2.so")); - $wd2hash = exec("git --git-dir $wd2path/.git rev-parse --short HEAD"); - $wd2link = "https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/php/wikidiff2/+/$wd2hash"; // Put the software in an array of form 'name' => 'version'. All messages should // be loaded here, so feel free to use wfMessage in the 'name'. Wikitext // can be used both in the name and value. $software = [ '[https://www.mediawiki.org/ MediaWiki]' => self::getVersionLinked(), '[https://php.net/ PHP]' => PHP_VERSION . " (" . PHP_SAPI . ")", - '[https://www.mediawiki.org/wiki/Wikidiff2 wikidiff2]' => phpversion("wikidiff2") . " ([$wd2link $wd2hash]) " . "(last built: $wd2mod)", '[https://icu.unicode.org/ ICU]' => INTL_ICU_VERSION, $dbr->getSoftwareLink() => $dbr->getServerInfo(), ];