On Tue, Jan 10, 2017 at 11:15:32PM +0100, Ludovic Courtès wrote:
> * gnu/packages/tls.scm (gnutls-3.5.8): New variable.
> (gnutls)[replacement]: New field.

> +(define-public gnutls-3.5.8                       ;fixes GNUTLS-SA-2017-{1,2}

Typically these replacements are not exported. The last time I noticed
an exported replacement, I found that it was resolved
non-deterministically (using `guix build -S` in a loop), and we made the
replacement private:

http://git.savannah.gnu.org/cgit/guix.git/commit/?id=69aa6e0995b55a38d5ce174602a107645be726d5