So I did it, I hung outside the Apple store with my laptop, checking in different versions to the sixtysecondshootertest.appspot.com directory and then going inside and running it on a Macbook Air. They were cool with that: "You don't mind?" I asked. "We don't mind! Enjoy yourself," they said.
I narrowed down to the revision that caused the problem, and my comment in the log is "I haven't checked in in a while."
Yep. Lot of changes in that revision, and I won't get a chance to work on it much more until Friday.
It's really easy to get out of the habit of checking in when I work alone. But, in theory, I should check in much more frequently, because my changes aren't going to break anybody.
Hopefully I've learned my lesson this time. I've just set my global ignores, and I'm going to try making add/commit a habit. I'm also checking my own copy of the nacl_sdk, so that will stay in sync too - when reverting these changes there were some include file differences between the version I was using and the version I'm using now, and I had to patch them by hand every time.
I just learned about mercurial and git the other day. (Wow, I used to keep so up-to-date on source control systems.) If I was working with anybody else I'd switch from subversion.
Meanwhile a friend asked me, "How many Mac users do you have?" When I started this project, about 25% of the visitors were Macs. Now it's down to 9%. (Part of the shrinkage, no doubt, is that the game doesn't work on Macs anymore.) "Screw 'em," he said. But I just can't. I have too many friends with Macs, for one thing.