在H3上(Ubuntu 16.04.2 LTS，内核版本3.4)使用命令apt-get install -y gcc-arm-linux-gnueabi安装交叉编译工具链，报错如下：
Package gcc-arm-linux-gnueabi is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'gcc-arm-linux-gnueabi' has no installation candidate
网络都是通的，源也更换过国内的试过，还是不行。
但是在虚拟机里能正常安装，这可能是什么原因呢?
