我在没有示例（this question）的情况下成功构建了shogun，但现在当我尝试使用元示例执行相同操作时，我收到如下错误：
$ cmake -DSWIG_EXECUTABLE=/usr/local/bin/swig -DINTERFACE_PYTHON=ON -DBUILD_META_EXAMPLES=ON ..
-- Could NOT find CCache (missing: CCACHE CCACHE_VERSION)
-- Using system's malloc
CMake Error at src/shogun/CMakeLists.txt:49 (MESSAGE):
Shogun can only be built with GPL codes if the source files are in
/Users/krishna/shogun/src/gpl. Please download or disable with
LICENSE_GPL_SHOGUN=OFF.
-- Configuring incomplete, errors occurred!
See also "/Users/krishna/shogun/build/CMakeFiles/CMakeOutput.log".
谢谢。