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Date: Thu, 21 Jul 2005 14:09:23 +1000 (EST)
From: Luke Kendall <luke DOT kendall AT cisra DOT canon DOT com DOT au>
Subject: Re: MD5 checksum question
To: cygwin AT cygwin DOT com
In-Reply-To: <20050721020211.GB21521@trixie.casa.cgf.cx>
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Message-Id: <20050721040923.E453F83CB3@pessard.research.canon.com.au>

On 20 Jul, Christopher Faylor wrote:
>  On Thu, Jul 21, 2005 at 11:13:26AM +1000, Luke Kendall wrote:
>  >Does it matter that the top-level setup.ini (that duplicates the MD5
>  >checksums of each package's md5.sum file), does *not* do the same thing
>  >for the setup.hint file in each package directory?  I assume the
>  >duplication is to allow the detection of the race condition (mentioned
>  >below).
>  >
>  >I only noticed while updating my md5cygchk mirror-checker, to detect the
>  >case where all package md5.sum files are correct but the top-level
>  >setup.ini file is out of sync with the packages below.
>  
>  Right.  setup.ini is only updated at regular intervals.  It doesn't
>  get updated on a continuous basis.  So, there will be times when
>  the md5sums (and version and sdesc and ldesc and tar ball) in setup.ini
>  do not match setup.hint.

Thanks.

I'm currently trying to find out why a recent copy of a cygwin mirror
causes the "Download Incomplete.  Try again?" error.  The md5 checksums
on each file within the download is good (checking them against the
md5.sum file in each package directory).  But still we get the above
error.

By looking through the mailing list archives, I got the impression that
this happened when the setup.ini file got out of sync with the
collection of packages - I imagined (wrongly, from what you've
explained above), that they should agree, so I modified my script to
check.

Clearly, from what you've explained, that's the wrong thing to do.

Is there a way to test if a cygwin mirror you've downloaded is
internally consistent, other than by running setup.exe?

Or perhaps a better question is: is there a way to test if a 
downloaded cygwin will cause the "Download Incomplete.  Try again?" error?

We mirror nightly via rsync (which often breaks due to incomplete
upstream mirror), have a stable working Cygwin (ours is Sep 29 2004),
and now and then snapshot a good nightly mirror to become a release
candidate for the next stable working version.  Unfortunately, this rc
version is getting the "Download Incomplete.  Try again?" problem.

>  >(This happens if you rsync a mirror site while the site is being
>  >updated.  It leads to the setup.exe error: 
>  >"Download Incomplete.  Try again?")
>  >
>  >I'm assuming the lack of a setup.hint line in each package's entry in
>  >setup.ini doesn't matter.
>  
>  The setup.hint file is what is implicitly placed into the setup.ini
>  file.  Somehow adding an md5sum for setup.hint into setup.ini doesn't
>  make any sense.  setup.hint isn't intended for use by anything other
>  than the process which constructs setup.ini.  There is no reason to
>  expose an external md5sum for setup.hint.

Thanks, that makes sense.

luke


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