And now you can use tmux in Cygwin.

I've been using it in Cygwin for a long time. What is supposed to be broken?

That's strange. The patch that allows it to work has only existed for less than a year. Tmux apparently passes file descriptors over unix domain sockets, which isn't supported by Cygwin.

Well by long time I mean several months. Happy coincidence I guess.

How?

Check the changelog again. Normal changes, point #4:

* Tmux now runs under Cygwin natively.

i highly recommend transparency about 85-90% on conemu if you use black/dark backgrounds. it really seems to save me some alt-tabs especially when following instructions.