Reportedly, Idf0a6547 causes insertDefaultSites to fail with an error:
"Warning: Invalid argument supplied for foreach() in /Library/WebServer/Documents/wikidata-repo/extensions/Wikibase/lib/includes/Utils.php on line 88"
I was not able to reproduce this, but to allow for easier investigation of the issue, I have submitted changes that report more meaningful errors on failure: Iab7e750e for Wikibase and Iad3995a6 for core. If you experience the problem described above, please patch these in and report your findings.
Version: unspecified
Severity: normal