Last modified: 2012-05-10 22:25:34 UTC
Go to https://en.wikipedia.org/wiki/Special:Version and click on the link that's the WM software version number in brackets - currently "(c29337d)". For me, at least, it leads to a gerrit.wikimedia.org page which just contains "400 - Unknown action". Presumably it's not meant to do that.
This is because the clones on fenari are being weird and creating merge commits all the time, even though I can't actually find any divergence between the local branch and the origin. I'll investigate a bit more.
*** This bug has been marked as a duplicate of bug 36575 ***