From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Referring to revisions in the git future. Date: Tue, 28 Oct 2014 23:05:57 +0000 Message-ID: <20141028230557.GC6630@acm.acm> References: <20141028223312.GB6630@acm.acm> <87tx2n7qlg.fsf@wanadoo.es> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1414537620 8952 80.91.229.3 (28 Oct 2014 23:07:00 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 28 Oct 2014 23:07:00 +0000 (UTC) Cc: emacs-devel@gnu.org To: =?iso-8859-1?Q?=D3scar?= Fuentes Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Oct 29 00:06:53 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XjFqn-0007Nc-8I for ged-emacs-devel@m.gmane.org; Wed, 29 Oct 2014 00:06:53 +0100 Original-Received: from localhost ([::1]:41748 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XjFqm-0005u0-QP for ged-emacs-devel@m.gmane.org; Tue, 28 Oct 2014 19:06:52 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46903) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XjFqe-0005tn-TJ for emacs-devel@gnu.org; Tue, 28 Oct 2014 19:06:50 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XjFqZ-0001d8-LZ for emacs-devel@gnu.org; Tue, 28 Oct 2014 19:06:44 -0400 Original-Received: from colin.muc.de ([193.149.48.1]:42509 helo=mail.muc.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XjFqZ-0001cz-CE for emacs-devel@gnu.org; Tue, 28 Oct 2014 19:06:39 -0400 Original-Received: (qmail 39189 invoked by uid 3782); 28 Oct 2014 23:06:37 -0000 Original-Received: from acm.muc.de (pD9519FE5.dip0.t-ipconnect.de [217.81.159.229]) by colin.muc.de (tmda-ofmipd) with ESMTP; Wed, 29 Oct 2014 00:06:36 +0100 Original-Received: (qmail 7722 invoked by uid 1000); 28 Oct 2014 23:05:57 -0000 Content-Disposition: inline In-Reply-To: <87tx2n7qlg.fsf@wanadoo.es> User-Agent: Mutt/1.5.21 (2010-09-15) X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 8.x X-Received-From: 193.149.48.1 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:175948 Archived-At: Hello, Óscar. On Tue, Oct 28, 2014 at 11:54:19PM +0100, Óscar Fuentes wrote: > Hello Alan, > Alan Mackenzie writes: > > Hello, Emacs. > > We are switching to git, soon. > > git doesn't have revision numbers. Instead it uses cryptic identifiers, > > which are not very useful in day to day conversation. A bit like in > > George Orwell's "Newspeak", where lingusists constantly removed words and > > meanings so as to render certain notions literally inexpressible, we seem > > to be faced with the same situation. > > On this list, one quite often sees statements such as: > > "That was fixed in revision 118147, have you updated since then?" > > or > > "The bug seems to have been introduced between 118230 and 118477. > > Maybe you could do a bisect to track it down.". > > Is it going to be possible to express such ideas in our git world, in any > > meaningful way? If so, how? Does git have a useable way of mapping its > > cryptic revision identifiers to monotonically increasing natural numbers, > > or some other useable scheme? > > I have bad feelings about this. > Before switching to git mayself the lack of revision numbers was the > strongest perceived inconvenience. Afterwards, it wasn't that bad. First > of all, you need to realize the limitations of using revision numbers: > they are meaningful only on the context of a branch. As soon as you have > more than one branch and merge among them, revision numbers are an > inconvenience. We've more than one branch in our Emacs repository, yet the bzr revision numbers are not in the slightest inconvenient. > As you use Mercurial, which has revision numbers, the advice of the > Mercurial experts possibly have some weight for you: > http://mercurial.selenic.com/wiki/RevisionNumber > Revision numbers referring to changesets are very likely to be > different in another copy of a repository. Do not use them to talk > about changesets with other people. Use the changeset ID instead. That is a bit like saying, instead of saying "tomorrow at 8 o'clock", which is horribly ambiguous, you should instead say at time 238707724383 (i.e. number of seconds after 1970-01-01, or whenever it was). Changeset IDs are good for some things, bad for others. > OTOH, there was some discussion on this list about using some > tool-independent schema, using a combination of the author's e-mail and > a timestamp. Are they going to enable the sort of conversation I exemplified above? -- Alan Mackenzie (Nuremberg, Germany).