Unnecessary duplication of SWIG command?

[mattagape]

In liblx/src/bindings/python/CMakeLists.txt, and presumably in the equivalent in libSBML, there are two invocations of the swig executable, like:

  COMMAND "${SWIG_EXECUTABLE}"
    ARGS  -I${CMAKE_CURRENT_SOURCE_DIR}/../swig/
        -I${CMAKE_CURRENT_SOURCE_DIR} 
        -I${CMAKE_CURRENT_BINARY_DIR} 
        ...

One of these invocations has the -DGENERATING_DOCS option.

Do we need to invoke swig twice like this?

This does not appear to be a problem with the other bindings.