From: Joshua Haberman <joshua@...>
Date: 2006-11-07T07:07:24+09:00
Subject: Re: merge YARV into Ruby

On Mon, 2006-11-06 at 13:55, Brian Mitchell wrote:
> I agree enough with some of that though I wouldn't say Darcs doesn't
> scale well (in comparison to svn) at this point.

After I heard about the "poison patch" problem with Darcs, I basically
stopped using it immediately and considered it unsuitable for pretty
much anything.  I don't know how well-documented this problem is, but
here is how one random person describes it:

http://sayspy.blogspot.com/2006/08/comparing-mercurial-to-bazaar-ng.html

"Well, Darcs suffer from a little advertised problem, known as the
"poison patch". With a Darcs repo, you can end up in a situation where a
particular checkout will take hours to days (and maybe eventually fail).
This happened to one of my important Darcs-controlled project, and I can
assure you that once it happened, you don't want to happen again. I
should add that it is not predictable, so it can happen anytime."

Yes, this is a informal comment on someone's blog, but I also see the
problem referred to in this post to darcs-users, along with a proposal
to address the problem:

http://www.abridgegame.org/pipermail/darcs-users/2006-February/009454.html

"I think there is a
lot of potential here, but kept my initial proposal very basic and the
minimum to help prevent the 'poison patch' problem which has been a
serious issue in practice."

I know my sources are somewhat hearsay, but I find this problem
believable given what I know about Darcs and its theory of patches.  I
would be very wary of trusting anything to a system that unpredictably
becomes unusable.

Josh