From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Enge Subject: Re: Package API compatibility and guix package variable names Date: Wed, 27 Jul 2016 23:33:02 +0200 Message-ID: <20160727213302.GA9807@solar> References: <20160719205719.20769-1-rekado@elephly.net> <87y44wdr1f.fsf@elephly.net> <20160727175431.35fc6326@scratchpost.org> <20160727161918.GA5300@solar> <20160727230615.33d2adc3@scratchpost.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:42197) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bSWRz-0003vJ-P7 for guix-devel@gnu.org; Wed, 27 Jul 2016 17:33:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bSWRv-0001Ok-Fg for guix-devel@gnu.org; Wed, 27 Jul 2016 17:33:10 -0400 Received: from mailrelay1.public.one.com ([91.198.169.124]:49868) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bSWRv-0001O9-45 for guix-devel@gnu.org; Wed, 27 Jul 2016 17:33:07 -0400 Content-Disposition: inline In-Reply-To: <20160727230615.33d2adc3@scratchpost.org> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Danny Milosavljevic Cc: guix-devel Hello, just replying to part of your message, since I think there might be a misunderstanding: On Wed, Jul 27, 2016 at 11:06:15PM +0200, Danny Milosavljevic wrote: > Just to make sure: I'm not saying the API major number should absolutely be part of the name, I'm saying there should be version bounds for all the inputs of packages. The inputs of our packages are absolutely precise: They are given as scheme variables (which are, in a sense, a moving target, since their content changes over time; but they are completely fixed at any given point in time). So we have no way of saying, like in many other distributions, that the input is any "python >= 2 and < 3"; in fact, we are always saying "use exactly this Python, with this source, build system, inputs, etc.". If a package x has as input "python", this is the scheme variable of this name, which, in my current git tree, refers to a package containing Python 3.4.3, and nothing else. Another package y may have as input "python-2", which is a scheme variable containing currently Python 2.7.10. In core-updates, we updated python-2 to contain Python 2.7.11. So the input to package y, compiled in core-updates, is still called "python-2", but has actually changed. The variable names are just conventions; and it is almost a pure coincidence that they usually are the same as the "name" field of the package record :-) But maybe I simply misunderstood your comment. Anyway, upgrading has been working generally well so far. Also, it is not always easy to determine whether APIs are compatible or not, since they are not necessarily tied to major versions of the software. For instance, I think that anything (or almost) written for gmp-4 still compiles with gmp-5 or 6. But this requires some familiarity with the code, which I have in this case since I am following the gmp development. Apart from that, we have thousands of packages now, some of which are probably not familiar to anybody. I know that I packaged software of which I did not even understand the description, just because it was a prerequisite for something I am interested in... Andreas