[CMake] building an autoconf project with externalproject

I'm trying to get cmake to compile an autoconf external library that comes with my git repo. I've found an example on stackoverflow that supposedly works, but I get an error message saying no CMakeLists.txt exists in that directory. http://stackoverflow.com/questions/16604815/cmake-reuse-external

Re: [CMake] Using Qt5 with CMake

Hi Steve: If you remember my OP, I don't (yet) have access to Qt5 myself, but another PLplot developer does, and after I changed the Qt relevant part of our build system following the helpful advice I got on this list, he was able to refine my work so that PLplot now produces good "qt" PLplot dev