报错：E: Unable to locate package libprotobuf-dev
报错：hong@hong-virtual-machine:~$ sudo apt-get install libprotobuf-dev libleveldb-dev libsnappy-dev libopencv-dev libhdf5-serial-dev protobuf-compiler
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package libprotobuf-dev
E: Unable to locate package libleveldb-dev
E: Unable to locate package libsnappy-dev
E: Unable to locate package libopencv-dev
E: Unable to locate package libhdf5-serial-dev
E: Unable to locate package protobuf-compiler
解决方法一：
更新
sudo apt update
解决方法二：
更新
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
解决方法三：
查看你的虚拟机里的ubuntu是否联网
