This link does not lead to the expected, and required, collection of
.tar.lzma (or .tar.xz) archives. We do not support distribution in .7z
format; please refer to http://mingw.org/PackageIdentificationHOWTO for
details of our packaging standards.
The 7z has four lzma packages so you can just download once. I just update the html and upload the -src package also. Can you try again. Thanks.