I cannot build xz with guix 0.8.3: $ guix build xz ... ERROR: download failed "http://tukaani.org/xz/xz-5.0.4.tar.gz"; 403 "Forbidden" ...
I'm not sure if this can be solved by contacting the admin of that web, but I guess that bumping xz version to at least 5.0.8 (I checked it was possible to download this one) could fix this problem. -- Jan Synáček
