Sometimes docker build might suffer from a slow network connection to the official Ubuntu apt-source servers. In such case, we can specify an apt-source mirror server that is geologically nearer to us. In the following example, we specified an apt-source server that responds fast in China.You can specify the UBUNTU MIRROR with :code:`--build-arg UBUNTU_MIRROR` like the example below.
2. Run the Development Environment
Once we got the image :code:`paddle:dev`, we can use it to develop
Paddle by mounting the local source code tree into a container that