Well that was fun. Some time ago, while experimenting with pthreads, I manually compiled and installed PHP 5.5 on this server, not really considering that I would miss anything important in the process. Well, I did, and it took me the better part of three months to get around to fixing it. Not that I couldn’t, just that I didn’t have time.
Well, I made time, and it is fixed. Back to business as usual. (Also: I will not be experimenting on my production box again…)