Gah! It's 3 a.m. I've spent the last two hours troubleshooting an "adapted" function in Statusnet (yeah, I still use that). Traced the problem to a file that doesn't even belong to Statusnet, isn't in the path for Statusnet, and shouldn't be detected by Statusnet. It gets detected because it's called "settings.conf" and is higher in the file tree than Statusnet. Once I changed the filename, and the two lines of code in the program that actually uses the file, everything in Statusnet went back to normal.
The real head-scratcher is that the file has been in that location (and in use) for months. It should have caused problems last year, rather than waiting until the middle of May to cause problems.
I guess this one will fall into the "we'll never know" bucket as I'm not willing to pursue that minutiae that far into the rabbit hole. However, I will say that the Statusnet programmer may have been a bit presumptuous when thinking that the only program on the web server (using "settings.*") was his.
Bleh. I'm going back to sleep.