the use of Sys.signal in the backend (I'm guessing that is related to the support of the polling mode for jenga and OMake)
Python library are... well, disappointing. On that subject, it would be nice if we could test emacs on windows as well, and see how it goes. (I have an idea of some people who might be using it, I'll try to contact them)
See: https://sympa.inria.fr/sympa/arc/caml-list/2013-08/msg00088.html
Two problems here :