When I run
sudo apt-get install cmake
I get the following response:
Package cmake is not available, but is referred to by another package.This may mean the package is missing, has been obsoleted, or is only available from another sourceE: Package 'cmake' has no installation candidate
解决方法如下：
# apt-get update
# apt-get upgrade
# apt-get install <packagename>
这样就可以正常使用apt-get了～