removed symlinks of src/solver.h, src/solver.c, src/vec.c and replaced them by the actual files; I did that because in cygwin, ocamlc wouldn't find solver.h in #include "solver.h". I might be mistaken but it's the only thing I found to avoid the problem...
modified the uint64 typedef that was causing issues in cygwin+ocamlc. In fact, the #ifdef _WIN32 wasn't proper for cygwin builds; plus, the uint64 isn't standard, changed to uint64_t. See the SO topic here: http://stackoverflow.com/questions/126279