问题描述：
编译安装eigen，cmake时遇到如下问题：
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
GLUT_Xmu_LIBRARY (ADVANCED)
linked by target "openglsupport" in directory {$PATH}
-- Configuring incomplete, errors occurred!
系统环境：
ubuntu16.04
解决方案：
执行：
sudo apt-get install libxmu-dev
