Hey Emmanuel. FYI, I've just filed: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=962686
This is the C++ version, which seems however to contain also some Python SWIG bindings (but I have no idea whether these work or are complete - OTOH s2phere isn't complete either). My Python knowledge isn't really good enough to tell which version one should package respectively which is better. Cheers, Chris.