Hello,
Links on github for Required_xof2 is very slow in China. Download speed is about 10kb/s. And the links will be dead after about 20mins, and I have to start it over. So, clearly It’s IMPOSSIBLE for me to download it from amazon AWS(or whatever it is).
Do we have other mirrors? Or anything that help get the project?
Sorry about this. 
Some users in China have reported reasonably decent download speeds from GitHub, and others have said that it is completely unusable. We’re talking about how we can distribute the files using alternative methods, including allowing incremental updates to the dependencies, rather than having to re-download the whole thing every time. It will take us some time to figure this out though. Meanwhile I’d suggest grabbing a download manager plugin for your browser that can resume a download after the connection is interrupted. Firefox has quite a few free plugins like this available.
–Mike
You shall try some VPNs …
These packages are stored at Amazon Cloud, which is accessed slowly in China.