Re: CVS -> SVN -> Git

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 14, 2007, 20:58 UTC
Message-ID: <7vzm1yg0sj.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20070714195252.GB11010@thyrsus.com>

esr@thyrsus.com (Eric S. Raymond) writes:

Show 16 quoted lines

> So, I hear about plans to make cvs2svn generate something other than
> Subversion, and here's my instant reaction:
>
> 	    	       	   DON'T DO IT!
>
> This is not because I think Subversion is some kind of final answer to the
> VCS problem.  Fame from it -- I'm moving towards Mercurial.  No, the
> real reason I think this would be a waste of time is subtler than that.
>
> Subversion, by design, is very good at capturing the metadata from
> SCCS and RCS and the various CVS variants floating around.  In fact,
> lifting from those into Subversion is basically lossless - the real
> problems are that (a) as Michael notes, the data you're losslessly
> lifting is scratchy, and (b) as I've noted, you have to use heuristics
> to coalesce file histories into changesets and those don't always make
> the links they should.

Converting to Subversion might be lossless, but is it really the most convenient intermediate format for other people to convert further from?

Even after xxx2svn overcomes the problems (a) and (b) you noted above, my impression has been that svn2yyy needs to work harder than necessary to grok the branches/ and tags/ that artificially are flattened, only because Subversion does not do branches nor tags, but just represents them as copies.