Hello Guix,

A while back I toyed with the idea of a "Sources DVD" for Guix, much
like Trisquel has. While looking into the feasability of this, I
noticed that the git/svn/cvs/hg checkouts our packages use are not
compressed in the store.  So I wrote a simple script to compare the raw
size of all source checkouts with their corresponding xz-compressed
tarballs.  

At the time, I couldn't convince myself the trouble was worth the
effort; we had only 385MiB of uncompressed source checkouts, which
would compress to 135MiB.

Since that initial investigation, the number of packages using VCS
checkouts has risen from 50 to 389, and the on-disk size of that source
has risen to 3784MiB uncompressed.  We could compress that down to
538MiB.

Compression in not free, but I think it would be nice for our build
servers who have to store and serve (which, iirc, requires them to
compress it anyhow) this source.

What do people think?

`~Eric