Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Message-ID:	<41DD8D46.5010602@reservoir.com>
Date:	Thu, 06 Jan 2005 14:11:02 -0500
From:	Richard Lethin <lethin AT reservoir DOT com>
Organization:	Reservoir Labs, Inc.
User-Agent:	Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910
MIME-Version:	1.0
To:	Max Bowsher <maxb AT ukf DOT net>
CC:	cygwin AT cygwin DOT com, unison-users AT groups1 DOT vip DOT scd DOT yahoo DOT com
Subject:	Re: problems with overloading of the semantics of version number in cygwin/unison
References:	<41DD5107 DOT 8060002 AT reservoir DOT com> <004c01c4f403$6d425740$5308a8c0 AT robinson DOT cam DOT ac DOT uk> <41DD5B6D DOT 9080909 AT reservoir DOT com> <012a01c4f422$7b537930$5308a8c0 AT robinson DOT cam DOT ac DOT uk>
In-Reply-To:	<012a01c4f422$7b537930$5308a8c0@robinson.cam.ac.uk>

Max Bowsher wrote:

> Richard Lethin wrote:
> 
>> Max Bowsher wrote:
>>
>>> Richard Lethin wrote:
>>>
>>>> There is a problem with the way that cygwin is updating the version
>>>> numbers for cygwin/unison.  Unison is used to synchronize filesystems;
>>>> it can cross different operating systems over IP.  The protocol uses 
>>>> the
>>>> version number to decide whether two processes on different systems 
>>>> will
>>>> communicate.  2.9.1 is the official released version.  There is a beta
>>>> version 2.10.2, but it is not widely deployed.  Thus people (like me)
>>>> will want to use the 2.9.1 version of cygwin's unison.  However, cygwin
>>>> is numbering its instance of this version 2.9.20-1.  When you try to
>>>> communicate using cygwin's 2.9.20-1 with a standard 2.9.1 version of
>>>> unison running on another system, the communication fails after the
>>>> handshake when it discovers that the cygwin version is "2.9.2 [sic]".
>>>> Yes, I think that the handshake is truncating the protocol string.
>>>>
>>>> Anyway, my suggestion is that cygwin update the version of 2.9.1 
>>>> that it
>>>> is distributing, to separate the overloaded concept of version number
>>>> into a cygwin version number (which could then be arbitrary) and leave
>>>> the protocol number at 2.9.1
>>>
>>>
>>>
>>> No, this is nothing to do with cygwin, and everything to do with
>>> unnecessary inflexibility in the version checking of unison.
>>>
>>> It would be a very bad thing for Cygwin to distribute a version of
>>> unison which lies about which version it is to the other end of the
>>> connection.
>>
>>
>> Sure, it's a bad design choice in unison, but cygwin is using the
>> version number in Unison - which means something about the protocol
>> version in unison - to mean something about the software release - which
>> operationally is not what unison really means.  The result is that
>> cygwin unison is broken.
> 
> 
> Unison itself uses the same version number for protocol of software 
> release.
> That is a problem if you cannot obtain unison binaries for all machines 
> you wish to synchronize between from a single source.
> Nothing in this problem is in any way cygwin specific.

Where does the version number 2.9.20-1 come from?

> 
> Cygwin unison works without problems with other copies of cygwin unison,

and this is only marginally useful.

> and any other platform's unison of the same version.

Right, but who else uses the version number of 2.9.20-1?

> 
> Max.
> 

-- 
Richard Lethin
Reservoir Labs, Inc.
+1-212-780-0527 ext. 102
www.reservoir.com

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -