How to let mbed use local library

I want to use mbed in my virtual machine, but after 4 hours, it doesn’t download the library from github.(Maybe the reasonis the poor internet of VMware). So I download it in my host computer from github, and copy it to the VM. But it’dosen’t works. mbed still.download from github though I have selected to use local library when I start a new program. How can I do?