执行cmake的时候出现下列错误

CMake Error at CMakeLists.txt:11 (message):
  
 
  FATAL: In-source builds are not allowed.
 
         You should create separate directory for build files.
 
 
 
-- Configuring incomplete, errors occurred!

　　则安装后先不要cmake

按照下列安装

$ cd opencv
 
$ mkdir build
 
$ cd build
 
$ cmake ..
 
$ make -j 10

　　替换安装的版本

sudo make install