Hello :)
we searched, and found many people with the same error, but with no solutions... perhaps someone can help us...
we get the following error, when we try to run the dumpHTML.php from shell (different working folders, same error):
Fatal error: require_once() [<a href='function.require'>function.require</a>]: Failed opening required '__DIR__/Maintenance.php' (include_path='.:/usr/local/lib/php') in /.../mediawiki/maintenance/commandLine.inc on line 24
kind regards, markus h.