CUPS won’t print more than one copy

I had two issues printing with CUPS on Arch Linux: When printing more than one copy, it always prints one. When selecting “Reverse” printing (that is, invert the order of the pages) didn’t work. It’s a bug in libcupsfilters 2.2. Reverting to version 2.1 fixed it for me. I’ve added it to an IgnoreGroup in my pacman.conf until it gets fixed. You should have seen me last Friday printing 20 copies of my Bible Study worksheet. One by one. Double-sided. Definitely not fun.