我有四个构建服务器，它们最初都设置相同。我们一直在使用它们来交叉编译 C 项目。我也在尝试更新它们以本地编译 C++。我能够在其中安装 g++ 的两台服务器上没有问题，但另外两台给了我 404 错误。
$ sudo apt-get install g++
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
g++-7 libstdc++-7-dev
Suggested packages:
g++-multilib g++-7-multilib gcc-7-doc libstdc++6-7-dbg libstdc++-7-doc
The following NEW packages will be installed:
g++ g++-7 libstdc++-7-dev
0 upgraded, 3 newly installed, 0 to remove and 5 not upgraded.
Need to get 9,043 kB of archives.
After this operation, 40.7 MB of additional disk space will be …