Generally when you want to pass extra definitions into `cmake`, you do it by passing them with `-DNAME=values`. This overwrites any previous value it may had, so make sure to include whatever is needed. ie
`cmake .. -DCC_EXTRA_OPTS= -DVERSION_NODATE`.
But then it should be used somehow from the `CMakeLists.txt` unless it's some standard variable.
See https://cmake.org/cmake/help/latest/envvar/CFLAGS.html#envvar:CFLAGS. Env variables can also be used to modify these flags.