From debbugs-submit-bounces@debbugs.gnu.org Wed Mar 18 16:36:31 2015 Received: (at 20137) by debbugs.gnu.org; 18 Mar 2015 20:36:32 +0000 Received: from localhost ([127.0.0.1]:51982 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YYKhb-00043G-DR for submit@debbugs.gnu.org; Wed, 18 Mar 2015 16:36:31 -0400 Received: from fencepost.gnu.org ([208.118.235.10]:39464) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1YYKhZ-000437-Am for 20137@debbugs.gnu.org; Wed, 18 Mar 2015 16:36:30 -0400 Received: from reverse-83.fdn.fr ([80.67.176.83]:56121 helo=pluto) by fencepost.gnu.org with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1YYKhY-0005wJ-Lz for 20137@debbugs.gnu.org; Wed, 18 Mar 2015 16:36:29 -0400 From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=) To: 20137@debbugs.gnu.org Subject: Re: bug#20137: number of generation doesn't always rise monotonically References: <20150318173550.GE525@venom.suse.cz> X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 28 =?utf-8?Q?Vent=C3=B4se?= an 223 de la =?utf-8?Q?R?= =?utf-8?Q?=C3=A9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 83C4 F8E5 10A3 3B4C 5BEA D15D 77DD 95E2 EA52 ECF4 X-OS: x86_64-unknown-linux-gnu Date: Wed, 18 Mar 2015 21:36:26 +0100 In-Reply-To: <20150318173550.GE525@venom.suse.cz> (=?utf-8?B?IlRvbcOhxaEg?= =?utf-8?B?xIxlY2giJ3M=?= message of "Wed, 18 Mar 2015 18:35:51 +0100") Message-ID: <87k2yedovp.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -5.0 (-----) X-Debbugs-Envelope-To: 20137 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -5.0 (-----) Tom=C3=A1=C5=A1 =C4=8Cech skribis: > 1] install some package (you'll have N and N+1) > 2] install some other package (you'll have N, N+1 and N+2) > 3] delete generation N+1 (you'll have N and N+2) > 4] switch to generation N > 5] install some package - you'll get generation N+1 again > (you'll have N, N+1 and N+2 again) That=E2=80=99s expected, yes. What makes you think it=E2=80=99s a problem? When implementing that, there were several possible choices: 1. Upon rollback to N, remove all generations above N. Rejected because it gratuitously prevents useful use cases. 2. Upon rollback from P to N, keep all the generations, but use P+1 for the next generation number. Doesn=E2=80=99t work, because rolling= back from P+1 would bring you back to P instead of N. 3. The current behavior. See for part of the discussion. Thanks, Ludo=E2=80=99.