[darcs-users] Converting foreign repos to Darcs

[Lele Gaifax]

On Fri, 07 May 2010 21:01:24 +0200
Ben Franksen <benjamin.franksen at bessy.de> wrote:

> Hello Darcsers
> 
> a few days ago I started converting a Subversion repo to Darcs. This
> did not go very smoothly. I used tailor as this seems to be the only
> existing tool for the job.
> 
> The conversion process went fine, however
> 
> (1) tailor ignores svn tags: they do not appear as darcs tags in the
> result

tailor was not born to replicate another repo kind. I didn't care at
all about tags. All tags support in tailor has been contributed and
happily merged in.

More, properly handling of svn tags is even more tricky than, say, CVS
ones, so I'm more than happy if some else wrote a working
implementation, something I'm surely not going to reinvent.

(2) when I tried to insert the missing tags manually, I found
> that the resulting darcs repo contains broken patches.

I would have written a pre/post commit hook, feeded with a parsed "svn
ls -v /tags" output, executing "darcs tag" at the right time.

But what do you mean with "broken patches"? I converted tons of svn
repos to darcs with tailor, and never had that bad experience (well,
almost :-).

> I tried to convert via other VCSes (bzr,hg). Conversion to bzr added
> the tags just fine, so I thought maybe tailor can convert from the
> bzr repo. Nope. It ran immediately into an error. Next thing I tried
> is to 'hg convert' the bzr repo to mercurial. Went through like
> butter. But when I tried to use tailor to convert from the resulting
> hg repo to darcs, ... well, by now you probably guess what happened:
> I got a stack trace saying something about some constructor not
> expecting 5 args but only 2. It turned out this is just bit-rot, as
> there was a change mercurial's python API some time ago.

Yes, I may understand the feeling. To fix that call, I'm inclined to
wait for hg 2.0 when hopefully they will get it right and written in
stone, or for an actual hg user (easy, I'd say) contribution,
whichever come first. :-)

> Next thing that happened was the tailor web page broke down, somehow
> trac runs into an error. Since this problem persists, I reported this
> to the tailor mailing list. While doing so, I found that there was
> just one other (un-answered) message with a 2010 date.

Yes, zooko sent me an email, and I restarted the apache daemon,
apparently stuck somewhere. Sorry about that.

And yes, tailor's mlist is very very quiet, always been like that. I
still hang on #tailor on irc.freenode.net, though.

> So, it appears tailor is no longer an actively maintained project.

Uhm, well, it's definitely not easy to admit, but yes, I could not
spend any more on it as I used to in the past. Primarily because I'm
finally and happily busy doing work-for-living, second because my
dependency on tailor is weak these days, as I currently do almost
everything in pure darcs, with a single on going experience with
bazaar.

That's probably make the project "no longer actively maintained".

OTOH, the section "The future" on the main wiki page stated that more
than 9 months ago.

So, little surprise there.

> I think this conversion business needs more serious attention from the
> community. For me it is a much heavier show-stopper than any of the
> performance problems.

I think the community, in particular you in this case, should first of
all respect whoever wrote some piece of software you happen to be
using. Darcs itself would be stuff of the past, if the community
simply shouted at David and his no-more-maintained-pile-of-bugs :-)

A supporting community can make the difference, as it can even take
over the maintenance effort, if convincing the author to keep it going
on is impossible for whatever reason. Even a single unsatisfied user
can make the difference, by choosing the right words to ask or propose
a fix.

Last, *maintaining* any amount of code is not just a matter of keeping
it inside the darcs repo. Expecially when that amount of code deals
with a versioning system. And really expecially when it deals with two
of those.

ciao, lele.
-- 
nickname: Lele Gaifax    | Quando vivrò di quello che ho pensato ieri
real: Emanuele Gaifas    | comincerò ad aver paura di chi mi copia.
lele at nautilus.homeip.net |                 -- Fortunato Depero, 1929.