Hello Guix!

Starting from now, the build farm at <https://ci.guix.gnu.org> provides
lzip-compressed substitutes in addition to gzip-compressed substitutes.

If your machine is running a recent Guix daemon (from the beginning of
June), substitutes you obtain will more and more frequently be lzipped.
Concretely, you’ll see messages like:

  downloading from https://ci.guix.gnu.org/nar/lzip/…

where the “/lzip” part indicates that this is an lzip-compressed
substitutes.

If you’re running an older Guix daemon, lacking lzip support, there
shouldn’t be any difference: you’ll download gzipped substitutes as
before.  However, we encourage you to upgrade your daemon.

Lzip¹ compresses significantly better than gzip, so you’ll have less data
to download when installing and upgrading software.  For example, the
Libreoffice substitute goes from 123 MiB to 89 MiB (-28%).

We may turn off gzip support on our build farm in a few months; we’ll
monitor gzip usage and give prior notice.

Please report any issues you encounter.

Ludo’.

¹ https://nongnu.org/lzip/