Re: git-svn breakage on repository rename

From: Eric Wong <normalperson@yhbt.net>
Date: Dec 5, 2009, 22:22 UTC
Message-ID: <20091205222251.GA2120@dcvr.yhbt.net>
In-Reply-To: <4B197078.6050203@cosent.net>

Guido Stevens <guido.stevens@cosent.net> wrote:

Show 25 quoted lines

> Hi Eric e.a.,
>
> I have a weird git-svn corner case that might interest you (or not at  
> all). I'd appreciate any help or hints for moving beyond this problem.
>
> I'm using git-svn to do a full commit history analysis of the Zope +  
> Plone CMS code bases as part of a research project with the University  
> of Nottingham into open source knowledge dynamics.
>
> One of the repositories I'm importing breaks with a "Checksum mismatch",  
> indicating a corruption. However, this error message occurs exactly at  
> the point where the repository was renamed: from "Products.CMFPlone" to  
> "Plone" (22715->22716). (Yes, it's the Plone core itself that resists  
> analysis :-()
>
> The git-svn url for the later commits would be:
>   http://svn-mirror.plone.org/svn/plone/Plone/trunk
>
> Whereas an older part of the code base lives at:
>   http://svn-mirror.plone.org/svn/plone/Products.CMFPlone/trunk
>
> Funny thing is, git-svn detects this rename upfront but then breaks
> anyway. Which raises the questions:
>
> - is this breakage caused by the rename?

Hi Guido,

Yes. By default, git svn without --stdlayout does not attempt to determine a repository root so parent following can be done. On the other hand, Plone does appear to use a standard SVN layout.

> - or does git-svn handle the rename, and there is an actual corruption?

It should, let me know if the example I give below doesn't work

It looks like a big repo and they're worried about bandwidth:
"Do not make a checkout of the entire repository! This is likely to
  get you blacklisted."
(ref: http://dev.plone.org/plone/wiki/RepoInfo)

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> - is there any way I can work around this and get a valid or semi-valid
> git history for this project?
>
> I don't mind missing a few commits, since I'm not doing code development
> on this repository, only statistical analysis.

I would mind very much if git svn missed commits :>

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> Solving this would also be helpful for anyone who wants to work on Plone  
> development through git rather than through raw svn.
>
> :*CU#
>
> ----------------------------------------------------
> To reconstruct this error:
> ----------------------------------------------------
>
> $ git svn init https://svn-mirror.plone.org/svn/plone/Plone/trunk Plone
> $ cd Plone
> $ git svn fetch

Since Plone appears to use a standard trunk/branches/tags layout recommended by SVN developers, can you try this instead?:

  git svn clone -s http://svn-mirror.plone.org/svn/plone/Plone

If you don't care about branches/tags at all, you can also try

  git svn clone --no-follow-parent \
    https://svn-mirror.plone.org/svn/plone/Plone/trunk Plone

Also, in the future it'd be nice to know which version of git svn you're using since bugs may be fixed in a newer version. Thanks!

-- 
Eric Wong