importDumps.php works, importDumps.php --uploads does not.
The first sign of trouble is
PHP Warning: XMLReader::open(): Unable to open source data in /srv/mediawiki/w/includes/libs/mime/XmlTypeCheck.php on line 158
On that line it's trying to read a file in /tmp that doesn't exist.
It's possible that we're passing in a missing image file or otherwise bad input, but even in that case I'd like the script to report and continue rather than error out. Or at the very least report something useful.