Where is the best place to download texlive-20170524-extra.tar.xz ?

[Brian Woodcox]

While installing guilds 0.15.0 I am getting an download failures for this 
package.

I am using the system init —substitute-urls=“http://berlin.guixsd.org” 
/mnt/etc/config.scm /mnt command, but I get an error saying that it tried to 
download the tarball from:

http://mirror.hydra.gnu.org/file/texlive-20170524-extra.tar.xz/….
http://tarballs.nixos.org/sha256/….

and failed for both url’s.

Thanks.