When Tuleap is running PHP 8.0, there is a fatal error on PHPWiki when displaying a diff:

Fatal error: Declaration of HtmlUnifiedDiffFormatter::_lines($lines, $class, $prefix = false, $elem = false) must be compatible with DiffFormatter::_lines($lines, $prefix = ' ') in /usr/share/tuleap/src/common/wiki/phpwiki/lib/diff.php on line 178