Well, what do you know. I started over from scratch and it worked!! No idea what was wrong before. Biggest changes were using vanilla install path and homebrew's sdl2 instead of SDL2.framework.
Steps to clean up and start over:
1. Deleted ~/.ivan from previous tries
$ rm -rf ~/.ivan
2. Deleted cloned ivan project
$ rm -rf ~/dev/games/ivan
3. Deleted SDL2.framework (and related) from /Library/Frameworks/ to make sure it doesn't interfere with homebrew's and cmake's find sdl2 routine.
$ rm -rf /Library/Frameworks/SDL2.framework
4. Make sure I have SDL2 installed via homebrew (brew list sdl2)
$ brew list sdl2
/usr/local/Cellar/sdl2/2.0.5/bin/sdl2-config
/usr/local/Cellar/sdl2/2.0.5/include/SDL2/ (70 files)
/usr/local/Cellar/sdl2/2.0.5/lib/libSDL2-2.0.0.dylib
/usr/local/Cellar/sdl2/2.0.5/lib/cmake/SDL2/sdl2-config.cmake
/usr/local/Cellar/sdl2/2.0.5/lib/pkgconfig/sdl2.pc
/usr/local/Cellar/sdl2/2.0.5/lib/ (4 other files)
/usr/local/Cellar/sdl2/2.0.5/share/aclocal/sdl2.m4
5. Clone ivan from git
$ git clone https://github.com/Attnam/ivan.git
6. Generate makefiles (I used the most vanilla commands this time, previously I customized path)
$ cd ivan
$ cmake .
Previously I had done
cmake . -DCMAKE_INSTALL_PREFIX=`pwd`
7. Build ivan
$ make -j
8. install and rejoice!
$ make install
$ ivan