DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:to:subject:mime-version:content-type
	:content-transfer-encoding:date:from:in-reply-to:references
	:message-id; q=dns; s=default; b=BmgMT3SsQKLdn7ZB7Qzgh2cFLPK1r5w
	ZBWVD77D2rbPX+Lfr2VjibLjLJxBBzZ9w2sWl3dSHyBTSmR/FsN4Q7WgYfTzltbs
	ro/YezoCCpEsCrM3NNx6/puTYqclviJoOlEDwlGQoCU2MXRCLimRFdlnt2pgLub9
	+Kw69auyOSAc=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
To: cygwin@cygwin.com
Subject: Re: Circular dependency with =?UTF-8?Q?mingw=36=34-x=38=36=5F=36?=  =?UTF-8?Q?=34-runtime?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Date: Wed, 02 May 2018 06:30:55 -0700
From: Kaz Kylheku <920-082-4242@kylheku.com>
In-Reply-To: <5ae8f950.1c69fb81.5f000.63ab@mx.google.com>
References: <9bbe5b31-7959-4b51-6319-efa82686c125@gmail.com> <5ae8f950.1c69fb81.5f000.63ab@mx.google.com>
Message-ID: <989579ad6aa1626381ed0023db89012b@mail.kylheku.com>
User-Agent: Roundcube Webmail/0.9.2
Content-Transfer-Encoding: 8bit

On 2018-05-01 16:33, Steven Penny wrote:
> On Tue, 1 May 2018 13:44:45, JonY wrote:
>> What is the actual problem you are facing?
> 
> i already described it: when 2 things depend on each other in this way, 
> that is
> an error:
> 
> http://wikipedia.org/wiki/Circular_dependency

Nowhere does this page substantiate what you're saying; it doesn't say 
that the existence of a circular dependency is /ipso facto/ a form of 
error.

If A cannot be used unless B is also installed, and if B cannot be used 
unless A is also installed, then there is a cycle in the dependency 
graph. The packaging system must express the cycle (and handle it). This 
means that if a user selects A for installation, it must be 
automatically accompanied by an installation of B, and vice versa.

If you say that the dependency which is stated in the package system is 
incorrect, then you have to prove that either A or B can be usefully 
installed by itself. (Or even both, in which case they are independent.)

If the circular dependency is right, but unwanted, it can only be broken 
by making some code changes in A or B, or both (and only then changing 
the dependency expressions at the package level). You can't simply say, 
"I don't like circular dependencies; I will break any cycles in the 
package system dependency definitions, whether or not they reflect the 
underlying packages".

The only situation in which that would be justified would be that the 
package system is too weak to deal with circular dependencies; it gets 
into an infinite loop or whatever, so cycles must be avoided.

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