[This documentation](http://www.cmake.org/cmake/help/v2.8.8/cmake.html#command:find_path) says it will search `<prefix>/include` for each `<prefix>` in `CMAKE_PREFIX_PATH`, plus each directory in `CMAKE_INCLUDE_PATH` and `CMAKE_FRAMEWORK_PATH`, and the same vars with `SYSTEM` in them, and finally, the `PATHS` and `INCLUDES` environment variables. But unless the vars are oddly named, there's no mention of any `lib` directories...

However, that being said, it does work for me as well. I'm not sure yet whether it's intended behaviour though.