The removal of testing for ncurses.h is incorrect: this should break the Linux build, where ncurses.h is indeed commonly located in /usr/include.

Not sure how to proceed here: if somebody would try to reproduce the problem, they would likely come up with a patch which is fairly different from the one you are proposing. 

So, Luis: are you interested in working out a complete and correct patch? If so, please start with generating one that is against the hg 3.2 branch (or perhaps even against the default branch). It's ok if you are not interested, in that case we'll need to wait for some other volunteer.