Autoconf/automake issues?
Apparently only the newest versions of autotools actually work. If you have issues with autothings, download the latest tar.gz release instead of cloning the git repository. The tar.gz releases have the autotools-generated stuff. The git repository doesn't because git is not a release, it's what is used to make releases.
For me, "autoreconf -i" solved initial autoconf problems. (On macOS 10.12.)
On Ubuntu 16.04, I had to manually create src/config.h.in in order to build, even after running aclocal, autoconf, and automake --add-missing.
I think I finally figured out what this is - If you keep getting syntax errors and the like, your platform probably does not provide pkg-config - If not, install it.