Re: What's cooking in git.git (Jan 2013, #08; Tue, 22)

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 23, 2013, 00:11 UTC
Message-ID: <7vobgglpv4.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130122234554.GI7498@serenity.lan>

John Keeping <john@keeping.me.uk> writes:

Show 25 quoted lines

> On Tue, Jan 22, 2013 at 02:44:48PM -0800, Junio C Hamano wrote:
>> * jc/cvsimport-upgrade (2013-01-14) 8 commits
>>  - t9600: adjust for new cvsimport
>>  - t9600: further prepare for sharing
>>  - cvsimport-3: add a sample test
>>  - cvsimport: make tests reusable for cvsimport-3
>>  - cvsimport: start adding cvsps 3.x support
>>  - cvsimport: introduce a version-switch wrapper
>>  - cvsimport: allow setting a custom cvsps (2.x) program name
>>  - Makefile: add description on PERL/PYTHON_PATH
>> 
>>  The most important part of this series is the addition of the new
>>  cvsimport by Eric Raymond that works with cvsps 3.x.  Given some
>>  distros have inertia to be conservative, Git with cvsimport that
>>  does not work with both 3.x will block adoption of cvsps 3.x by
>>  them, and shipping Git with cvsimport that does not work with cvsps
>>  2.x will block such a version of Git, so we'll do the proven "both
>>  old and new are available, but we aim to deprecate and remove the
>>  old one in due time" strategy that we used successfully in the
>>  past.
>> 
>>  Will merge to 'next'.
>
> Would you mind holding off on this?  As it stands there are a couple of
> issues with the cvsimport-3 script including: ...

Actually I do. I think this, at least the early part of it, should be merged to 'next' as soon as possible, *unless*

 (1) The cvsimport-2 & cvsps2 combo this series ships gives worse
     experience than cvsimport we ship in v1.8.1 to end users of the
     current cvsimport with cvsps2; and/or

 (2) The cvsimport-3 in this series, which is a copy of an older
     version of what Eric has, is so broken that we are better off
     starting cvsimport-3 by getting a fresh copy from Eric which
     has been rewritten in a major way, than applying huge
     incremental update patches that amounts to a total rewrite.

The point (1) is important from "no regression" point of view, and in a sense more important between the two because it is the first step in the overall transition plan.

Even though there may be remaining issues in cvsimport-3 and cvsps3 (what new piece of software don't have issues?), my limited observation of the exchanges between you and Eric suggests me that the problem is not something that requires a total rewrite of how cvsimport-3 works, so I do not expect the point (2) to be true, either, but if I am mistaken, please let me know.

By advancing the topic to 'next', we will give people a more solid (read: not getting rewound) foundation to work with than "if you are really interested, grab the tip of 'pu', replace it with even newer copy from Eric's repository and try it out", so that more people can help us polish the scaffolding to let us ship two versions and also find issues in the new cvsimport-3 and help fixing them. At least, that is what I've been hoping.

I could stop at the first three patches, that is, introducing the version switch wrapper that switches between cvsps2+cvsimport-2 combo and nothing, and then let you and Eric redo the "start adding cvsps 3.x support" and later patches when cvsimport-3 is ready. That would give you a larger lattitude to rework cvsimport-3. Is that preferrable?