From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pjotr Prins Subject: Re: Reproducible and deterministic builds for GNU Guix (and Nix) Date: Fri, 8 Apr 2016 21:52:56 +0200 Message-ID: <20160408195256.GA21804@thebird.nl> References: <20160408065934.GA18715@thebird.nl> <20160408194621.GA21757@thebird.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20160408194621.GA21757@thebird.nl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: erlang-questions-bounces@erlang.org Sender: erlang-questions-bounces@erlang.org To: Pjotr Prins Cc: guix-devel@gnu.org, Leo Famulari , Erlang , Magnus Henoch List-Id: guix-devel.gnu.org > also be changed). I guess you need it for hot reloading, but can't you > calculate the SHA on the fly for that? You'd need to open beam files > anyway to get the value(s) and they will be loaded by the OS unless Aw, sorry Joe, my bad. The stored SHA value is calculated on the original source file, so that is not opened. Guix/Nix calculate their SHA values over the source and build environment and that path is stored in an immutable store. So, you already have a strong guarantee that the sands don't shift under you. But then people will use Erlang outside GNU Guix - and there a SHA value makes sense if you watn to have a guarantee that it has the same source. Much better than a time stamp. Pj.