Re: Import ClearCaase with history?

[Peter Baumann <waste.manager@gmx.de>]

On Wed, Mar 31, 2010 at 06:33:09AM -0500, David Hagood wrote:
> I am trying to drag where I work into a more modern software development
> process, but I am getting resistance from one division that has a large
> amount of history for some projects in a Clearcase repository. If I
> could show them that we could import all that history into git, it would
> go a long way to removing that resistance.
> 
> I've seen programs that purport to import Subversion (which is also
> good, as they also are using Subversion for other projects....) but do
> any such programs exist for Clearcase?
> 
> I know that, in theory, it would be possible to 
>   for all checkins to Clearcase
>      check out of Clearcase
>      check into git
>   done
> 
> but that would take an incredibly long time in practice, wouldn't it?
> 

I don't think you can build anything which will import from ClearCase 
*without* loosing *some* history. At least I have build a script which imported
something from CC into git in my former job and allow me to sync bidirectional
with CC. 

The problems where no bidirectional mapping exists are the following:

  - CC is file based, where as GIT is tree (the whole repository) based

  - This leads to problems where you merge a file on differen CC branches,
    because in GIT a merge is only on the whole tree, so at least this
    information is lost. (see cleartool lstree for a file with merges)

Peter