From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Allan Webber Subject: Re: Version numbers for VCS snapshots Date: Sun, 21 Feb 2016 16:09:58 -0800 Message-ID: <87si0lbo4r.fsf@dustycloud.org> References: <874mem8mwx.fsf@gnu.org> <8737u344ov.fsf@elephly.net> <87twmjp2qs.fsf_-_@gnu.org> <56A063D1.80608@uq.edu.au> <20160121062251.GA25513@jasmine> <20160121184424.GB12122@jasmine> <87fuxqwsm7.fsf@gnu.org> <20160221043515.GA17164@jasmine> <87bn7axw0w.fsf@gmail.com> <20160221225256.GA21678@jasmine> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:60891) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXe5g-0004Uo-FC for guix-devel@gnu.org; Sun, 21 Feb 2016 19:11:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aXe5f-0002Or-B2 for guix-devel@gnu.org; Sun, 21 Feb 2016 19:11:04 -0500 Received: from dustycloud.org ([2600:3c02::f03c:91ff:feae:cb51]:53514) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXe5f-0002OV-3u for guix-devel@gnu.org; Sun, 21 Feb 2016 19:11:03 -0500 In-reply-to: <20160221225256.GA21678@jasmine> 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-bounces+gcggd-guix-devel=m.gmane.org@gnu.org To: Leo Famulari Cc: guix-devel@gnu.org, Alex Kost Leo Famulari writes: > On Sun, Feb 21, 2016 at 12:17:19PM +0300, Alex Kost wrote: >> Leo Famulari (2016-02-21 07:35 +0300) wrote: >>=20 >> > On Thu, Jan 21, 2016 at 10:05:36PM +0100, Ludovic Court=C3=A8s wrote= : >> [...] >> >> I prefer 7! This is how Git usually truncates SHA1s, so it can=E2=80= =99t be wrong. >> > >> > I stumbled across this email earlier, which reminded me of this >> > discussion about hash lengths: >> > https://lkml.org/lkml/2010/10/28/287 >> > >> > There are currently 13 7-character hash collisions in Guix's git rep= o: >> > >> > $ git rev-list --objects --all | cut -c1-7 | sort | uniq -dc >> > 2 0d2b24c >> > 2 11e0632 >> > 2 1f3ab8d >> > 2 229bd6c >> > 2 7c4a7b7 >> > 2 9ff8b63 >> > 2 aa27b56 >> > 2 c10c562 >> > 2 d96cdce >> > 2 dab4329 >> > 2 dc27d1c >> > 2 ea119a2 >> > 2 f56cc27 >>=20 >> Hm, when I tried "git rev-list --objects --all" I got some ridiculous >> number of lines (I pressed C-c C-c after about 78000 lines). Does thi= s >> command really do what you wanted? (I'm sorry I didn't RTFM well enou= gh >> to understand what it does). > > It lists the objects in the repository, so not just commits. I'm not > presenting this as evidence that something is wrong with our repo, just > that 7 characters is not enough to unambiguously refer to things in git > repos of projects our size. For example, with `git show`. > > It's more of an informational link than a call to action. Although I am > updating all of our uses of git-reference to use the method we agreed > upon upthread, before any of those upstream repos grow too large for th= e > identifiers we are currently using. Yes, short identifiers probably should not be relied upon. For an entertaining article on the subject, I offer this one, which is similar but in GPG land: http://www.asheesh.org/note/debian/short-key-ids-are-bad-news.html