[Nix-dev] Updating emacs-snapshot package

[Shea Levy]

On 1/18/12 3:14 PM, Ludovic Courtès wrote:
> Hi,
>
> Phil Hagelberg<technomancy at gmail.com>  skribis:
>
>> Is it just discouraged to package prerelease versions of software in
>> general? If it's merely a question of stability then it shouldn't be a
>> problem; the Emacs 24 pretest is very stable.
> For GNU packages, I find it better to simply use whatever’s available
> from<http://hydra.nixos.org/project/gnu>.

How do I add such packages to my configuration.nix?