> I checked and everything looks all right, but I've been fighting for > 1+ hours because it cannot generate the ftgl.pdf documentation.
Hmm, simply "./autogen.sh && ./configure && make -j" does build it for me (though with some warnings), using stretch. Does that work for you? If so, it must be something in the Debian rules; otherwise it seems to be difference between stable and testing which may be worth investigating as it may affect others too. What errors do you get? Cheers, Frank