用Cmake编译文件，提示这个

我已经执行过git submodule update --init命令了，还是提示这个

CMake Error at CMakeLists.txt:87 (message):
Git submodules not initialized, execute:

git submodule update --init

-- Configuring incomplete, errors occurred!

https://stackoverflow.com/questions/17441904/git-submodules-in-gitmodules-not-initialized/17442045#17442045