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Interview: David Roundy of Darcs Revision Control

samzenpus posted more than 9 years ago | from the what-did-he-say dept.

Programming 173

comforteagle writes "In the aftermath of our last interview with Tom Lord, regardless of personalities, it became apparent that the idea of decentralizing CVS is a big deal. Many mentioned darcs as an alternative to Arch. Mark Stosberg has interviewed project head-hancho David Roundy about darcs, his 'theory of patches,' what's next, and on using Haskell for the project."

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173 comments

CVS (1)

CodeYoddler (674760) | more than 9 years ago | (#10916123)

CVS is getting pretty old, I bet it will be replaced soon by 40 different things.

Re:CVS (2, Interesting)

stoborrobots (577882) | more than 9 years ago | (#10916484)

The Future was here in 1996 - Check out Reliable Software's Code Co-op [relisoft.com].

The Peer-to-peer Version Control System for Distributed Teams
Code Co-op is the version control system for distributed development that adds mobility, simplicity, and robust functionality to your Windows development projects.
  • Mobility for collaboration from any location using your existing infrastructure
    - no server required;
  • Simplicity to give you quick access to project files and history regardless of a network connection;
  • Robust functionality to give you all the control and security you require for managing your software assets.

With Code Co-op you can:
- Collaborate from anywhere using Email, LAN, and VPN
- Access your project files and history without a network connection
- Review file changes with the built-in Visual Differ or Beyond Compare Differ
- View, compare, or restore any iteration of your project or file regardless of a label
- Integrate with your favorite development tools
- Forgo costly server maintenance
- Rely on a secure, fully transactional database with automatic back-ups
- Implement source control in minutes for only $159 per user

Re:CVS (0)

Anonymous Coward | more than 9 years ago | (#10916603)

Sounds a lot like Sun's TeamWare (TeamWear?) from about '90 or so.

Already happened (1)

Hammer (14284) | more than 9 years ago | (#10916585)

In my systems and my company CVS has long since been replaced with subversion [tigris.org]. This is a OSS replacement that fixes CVS's shortcomings (such as atomic check in and directory versioning) It works real well, i'll never turn back.

Re:CVS (0)

Anonymous Coward | more than 9 years ago | (#10917567)

I wouldn't know, I'm still using bare-bones RCS for my projects. ;)

Redundancy is an absolute necessity. (-1, Offtopic)

Romancer (19668) | more than 9 years ago | (#10916137)

Redundancy is an absolute necessity.

We face the slow but steady erosion of our rights and our liberties. When we all stand together and back eachother, we decentralize, and with that we slow the forces that would undermine our ability to create our potential.

Re:Redundancy is an absolute necessity. (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#10916211)

shut it you stupid fucken kike nigger

mod parent up! (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#10916501)

I hate stupid fucking kike niggers; they should shut the fuck up.

Parent is ON TOPIC (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#10916268)

I am not Romancer. I just think it's unfair that his post has been moderated as "Offtopic", and ask that metamoderators mark the moderation as "unfair."

The performance of the internet free software development world is largely due to diff, patch, TCP/IP, the web, cvs and email. The adoption of usenet and the internet facilitated the rapid development of free software and the political consequences of that, which we are only beginning to experience.

Other software being developed right now will effect the outcome of political battles that will determine to what degree computers will allow or prevent oppression. For example, will people who do not wish to participate in software patents be allowed to organize and form their own country or will there be no escape for the "pirates"?

If you want software develop software to allow anonymous speech, free markets, or preservation of oppressed data, then you are in a deployment race. The software has to become quickly ubiquitous so that enough people will care when others try to make the government deter it. Getting that rapid adoption, is a deployment race and also a development race, and that will be made up of little battles like whether some new cryptographic feature get well into integrated into the a chat system in two months versus six months, which in turn is a function of how efficiently contributor effort is organized in projects that do not want to have a single attack point for adversaries to focus on, which, in turns is likely to be effected by decentralized version control.

I think (1)

9-bits.tk (751823) | more than 9 years ago | (#10916144)

that a system of round-robin mirroring should be implemented, if CVS doesn't go decentralised.

You could create a CVS cacheing service, a bit like Coral.

Mature RCS? (1, Offtopic)

phoenix.bam! (642635) | more than 9 years ago | (#10916155)

When do you move to your own RCS ro support it's own code? Kinda like bootstrapping the RCS? I really have no idea what i mean, but yeah, you get the idea. Did ARCH start out in a CVS somewhere? and where was bitkeeper kept in its infant days?

Self-hosting (3, Informative)

Earlybird (56426) | more than 9 years ago | (#10916375)

I believe the term you're looking for is self-hosting. Subversion, for example, was originally maintained in CVS, and has a CVS gateway for maintaining redundant systems.

For pilot-testing a migration to Darcs, there are scripts available that convert other repository formats (Subversion, CVS, possibly others) into Darcs (and back, actually), so you avoid losing history when making the transition.

Re:Mature RCS? (1)

Vintermann (400722) | more than 9 years ago | (#10916915)

GNU Arch has hosted itself for a very long time. As far as I know, it has never been publicly hosted in a different RCS. What, if anything, Tom Lord used to host it on his machine before the intial release, you'd have to ask him.

Re:Mature RCS? (1)

onesandzeros (445024) | more than 9 years ago | (#10917078)

>>Did ARCH start out in a CVS somewhere?

BitKeeper would have been a good example here, because iirc, there's something in the BitKeeper licencse that forbids its use to develope other RCS apps. I realize that the licenses of cvs, arch, subversion (all gpl?) don't have such restrictions, but if I do indeed recall correctly, and I'd like to think that I do, it would be interesting to see how McVoy used someone else's RCS to develop his own, which then, by virtue of its license, can't be used to make another RCS.

Re:Mature RCS? (2, Informative)

David Roundy (34889) | more than 9 years ago | (#10917422)

Actually, whether or not an RCS is self-hosting is a pretty useless test of the maturity of that RCS. It is incredibly easy to self-host an RCS, since the users are the developers. Darcs was self-hosting way back before I would even have considered suggesting that anyone else consider using it (as I'm sure was the case with Arch).

The hard part of writing an RCS is dealing with all those users who do things you never would have thought of, uncovering all sorts of interesting bugs.

Haskell just won't cut it (2, Insightful)

PhYrE2k2 (806396) | more than 9 years ago | (#10916156)

While "Darcs is written in a Haskell, a functional language that is relatively unknown compared to C or Perl", this really does hurt it's common use. Not being able to get a larger group of developers such as C, C++, or even some interpreted projects means that it becomes one or a few developers working on this project which means fewer patches and additions. A community project will ultimately be the versioning system for community projects. -M

Re:Haskell just won't cut it (5, Insightful)

QuantumG (50515) | more than 9 years ago | (#10916171)

So basically you didn't read the article. He gets more developers because it is written in Haskell than he would otherwise because it's one of the few real applications that are written in Haskell - which means if you're someone who just learnt Haskell for the hell of it you've got somewhere to apply those skills.

Re:Haskell just won't cut it (5, Interesting)

PhYrE2k2 (806396) | more than 9 years ago | (#10916256)

I did read the article, however I do DISAGREE with that comment in the article. People won't learn a language for one program, and there is not a large enough body who know the language to really truly UNDERSTAND the program and enough about it to make modifications and additions to it. Compare that to a bunch of C/C++/Java/Perl developers with a massive community body, it's a lot easier to get people to contribute. -M

Re:Haskell just won't cut it (0)

Anonymous Coward | more than 9 years ago | (#10916287)

Haskell isn't mainstream like C/C++/Perl/Visual Basic, but there are a hell of a lot of people know it.

It's only one major OSS that's written in Haskell, the language itself is all over industry.

Re:Haskell just won't cut it (1, Interesting)

Anonymous Coward | more than 9 years ago | (#10916362)

It's only one major OSS that's written in Haskell, the language itself is all over industry.

In that case, it should be trivial for you to name several examples.

By the way, I've started down the path toward installing haskell a couple of times in an effort to try darcs, but gave up an hour or two in each time, because I do not want to run foreign binaries and therefore have to go through a pretty complex bootstrapping process to install haskell.

If darcs were written in any language that is already installed on my PC and had no other external dependency that I lack, I would probably at least have darcs installed on PC as well by now and might have become a darcs user. Granted, if running darcs were really that important to me (perhaps even if I did not have other doubts about darcs), I would spend a few days to really get Haskell and darcs installed, but it's not that important to me right now, and I think my calculation is probably typical of a potential user population that is probably a multiple of the size of the existing darcs population.

Now it might be that darcs would not be where it is today technical with the resources that were used to make it because Haskell is so much more super-productive of a language to work in, so the technical decision to go with Haskell really has maximized adoption or development or whatever metric you want to consider, although I would expect Haskell-based programs to be winning all sorts of evolutionary battles against competing projects, as seems to be the case with perl, python, zope, plone, and linux. The decision to use Haskell is a complex empirical judgement call that is not mine to make, but your omission of examples increases my skepticism.

Re:Haskell just won't cut it (2, Interesting)

Pseudonym (62607) | more than 9 years ago | (#10916419)

I'm not the grandparent poster. I am a long-time Haskell user, though.

Saying that Haskell is "all over industry" is a gross exaggeration. Anecdotal evidence from Haskell users is that they are all over industry, and they tend to use Haskell in their work, though not necessarily in code that other people see. I, for example, have been known to prototype algorithms in Haskell and then translate them into C++ for our product.

Having said that, there are several consultants out there who write custom apps for clients in Haskell, and at least two [aetion.com] companies [galoisconnections.com] who heavily rely on it.

It is fair to say that Haskell is all over academia, being used to solve difficult CS-like problems. However, academic uses tend not to impress people, even if it is the best tool for a particular job.

Re:Haskell just won't cut it (2, Funny)

Anonymous Coward | more than 9 years ago | (#10916653)

Seriously, you might consider giving Haskell a little more respect. This was the language used for not only the first but also second place winner for the ICFP Programming Contest this year.

http://www.cis.upenn.edu/proj/plclub/contest/res ul ts.php

You don't need as many programmers when you have this kind of tool in your hands.

Re:Haskell just won't cut it (4, Informative)

cduffy (652) | more than 9 years ago | (#10916298)

Some people will learn a language because they want to know a language that has that specific set of features, regardless of what applications have already been written in that language.

It's a small group, but if you've the only game in town (in terms of OSS projects for them to work with)... well, that works out pretty well for you!

No, if Darcs has any major issues, it's the RAM and CPU time requirements, some of which the design makes inherently unresolvable.

Re:Haskell just won't cut it (1)

ArbitraryConstant (763964) | more than 9 years ago | (#10916408)

" Some people will learn a language because they want to know a language that has that specific set of features, regardless of what applications have already been written in that language."

I learn languages because it's impossible to respond to zealots talking about their language of choice otherwise. It usually works pretty well because zealots of languages nobody knows tend to be used to pontificating at people that don't know anything about the language in question. They're not used to people that can respond.

That's why I don't know Perl... lots of people know it, lots of people like it, but no one's going to deffend it.

Haskell is actually okay. The problem with it is that because it's functional you often end up restructuring half the program for what would have been a trivial change in an imperative language. Also, I/O is EXTREMELY counter-intuitive. Because it's functional, it's supposed to be stateless. Wrapping your brain around stateless I/O is hard for most people.

The good thing about it is the patterns. You can provide arbitrarily many implementations of a function, and which one gets evaluated is based on matching the arguments. You can match against arbitrarily many arguments of any type. After you've done this a few times, you feel really dirty using nested conditionals.

Re:Haskell just won't cut it (4, Interesting)

Pseudonym (62607) | more than 9 years ago | (#10916454)

The problem with it is that because it's functional you often end up restructuring half the program for what would have been a trivial change in an imperative language.

While I don't disagree with this, there are some counter-arguments too:

  • If you find yourself doing that, you may have written your original program in an imperative style in the first place. Alan Holub's argument about getter/setter methods [javaworld.com] applies to declarative programming too. If you wrote in a more language-ideomatic style, you might not be facing a huge restructure at all.
  • Much the same problem can happen in imperative languages, only the class of changes which would trigger such a restructure are different. For example, in a non-GC'd language, you may end up restructuring your program if some critical data lifetime changes. Or, instead of restructuring your program, you might prefer to hack it up instead, making it less maintainable. (It might be argued that languages like Haskell, which discourage this kind of hackery, might be a good thing in the hands of a certain kind of programmer.)
  • Even if you do have to restructure half the program, tools like Haskell's type system make this a less painful task than it would otherwise be.

Knowing a language also means knowing what kinds of changes are painful and what kinds of changes are not. Knowing this in advance helps you write your programs to be more future-proof.

Re:Haskell just won't cut it (1)

ArbitraryConstant (763964) | more than 9 years ago | (#10916741)

"If you find yourself doing that, you may have written your original program in an imperative style in the first place."

That wasn't the cause. Naturally, this claim is completely impossible to back up without a protracted debate that would require me to post code. I'm not up for that, so I'm just going to leave this here.

"Much the same problem can happen in imperative languages, only the class of changes which would trigger such a restructure are different. For example, in a non-GC'd language, you may end up restructuring your program if some critical data lifetime changes."

Well, this is where good language choice comes in. C can be okay for flat problems, but yes, when it starts getting more complicated, switching to a garbage collected language is usually a pretty good idea.

And, yes, there are times when Haskell is a good language choice. When I say it's "okay", it means I wouldn't be opposed to using it for a problem to which it's well suited. The only language that gets higher praise than that from me is Python. :)

"Even if you do have to restructure half the program, tools like Haskell's type system make this a less painful task than it would otherwise be"

I don't necessarily agree with that.

In OO languages, you often have problems with restructuring, but it's not a fair comparison. Objects have state. That's what they're there for. It's a pain to restructure class hierarchies sometimes, but Haskell can't even solve problem to begin with.

Also, dynamically typed languages like Python also make restructuring easier (using C++/Java as a baseline).

Re:Haskell just won't cut it (1)

Pseudonym (62607) | more than 9 years ago | (#10917368)

That wasn't the cause.

Right, hence I said it "may" be the cause. :-)

Having said that, your code still might not have been as ideomatic as it could be. For example, what was originally just IO could end up as a huge stack of monad transformers by the time you're done. Making a type synonym for the monad in the first place saves you a lot of hassle down the track.

I don't necessarily agree with that.

I say this from bitter experience. There is many a time when I've had to thread something through a lot of code, and the compiler found every place where it was needed. No, it wasn't pleasant. But it worked first time.

Also, dynamically typed languages like Python also make restructuring easier (using C++/Java as a baseline).

On the other hand, in that situation the compiler isn't working for you. It isn't working against you, either, but a bug found for you is a bug you don't have to track down.

Well said, sir. [nt] (0)

Anonymous Coward | more than 9 years ago | (#10916754)

nt means there is NO text.

Re:Haskell just won't cut it (0)

Anonymous Coward | more than 9 years ago | (#10917449)

in a more language-ideomatic
I think you meant language-independent, rather than idiomatic.

Re:Haskell just won't cut it (1)

jpc (33615) | more than 9 years ago | (#10917135)


nested conditionals, well yes, you should use case statements anyway. But then I program in C like a functional programmer anyway to a large extent. Everyone should learn a functional language, just to help you think about things in different ways. And Haskell does have the best type system of any language I have used.

Re:Haskell just won't cut it (0)

pnot (96038) | more than 9 years ago | (#10916349)

You wrote:

I did read the article, however I do DISAGREE with that comment in the article. People won't learn a language for one program...

but the article says:

And in fact, there have also been developers who learned Haskell expressly for the purpose of contributing to darcs.

So either:

(1) You haven't read the article, or
(2) You have read the article, but you were incapable of comprehending that sentence, or
(3) You're calling David Roundy a liar.

I find it odd that you use phrases like "won't cut it" and "won't learn a language", as if this were all speculation. darcs has hit 1.0. People use it. It is actively developed by many people. People have learned Haskell solely to hack on it. The facts clearly contradict your unsupported assertions.

Re:Haskell just won't cut it (1)

Kesh (65890) | more than 9 years ago | (#10916368)

... or, he's using "people" in the general sense. Yes, a few people have and will bother to learn a new language just for this purpose. There are always exceptions to any statement.

However, that number will be very, very small, especially compared to the number who would likely be interested if it used a more common language.

Re:Haskell just won't cut it (2, Insightful)

Chuan-kai Lin (26774) | more than 9 years ago | (#10916668)

(arguments that Haskell will not cut it because it does not have a large user community)

I have to say that I am troubled by this kind of attitude, especially on Slashdot. True, open source is mostly about freedom, but it is also about diversity, about innovation, and about trying to do things the right way. Since when do we condemn a project to failure just because it makes a non-mainstream choice, even if the choice was preferred by the developers due to technical superiority?

How do you feel when PHBs assure you that bringing Linux into the server room is sure to fail because it is not mainstream like Windows?

Since when do we let that stop us?

Who cares? (1)

Julian Morrison (5575) | more than 9 years ago | (#10917319)

Sure, if he wants to get a couple hundred entry-level code grinders in a hurry, if he were a business hiring modular, replaceable Windows monkeys, then Haskell would make his life hard.

However, neither of the above apply. This is basically a hobbyist project, a rare and rarified subject in both its spheres (version control and Haskell), with considerable overlap between the academic C.S. community that truly understands either.

"People won't learn a language for one program"? Not even if that program is one of the few and best in their area of expertise? Not even the handful of people needed to keep alive a tightly focused project like this?

MOD PARENT DOWN (0, Flamebait)

Anonymous Coward | more than 9 years ago | (#10916215)

RTFA

Re:Haskell just won't cut it (2, Insightful)

Pseudonym (62607) | more than 9 years ago | (#10916240)

Just like how nobody uses CVSup because it's written in Modula-3, right?

Re:Haskell just won't cut it (5, Insightful)

pnot (96038) | more than 9 years ago | (#10916291)

You wrote:
While "Darcs is written in a Haskell, a functional language that is relatively unknown compared to C or Perl", this really does hurt it's common use.

How will the choice of language hurt darcs's use? Why on earth would the users of a piece of software care about the language it's written in?

You wrote:
Not being able to get a larger group of developers such as C, C++, or even some interpreted projects means that it becomes one or a few developers working on this project

From the article:
I've been surprised by the number and quality of contributors darcs has had. There seem to be quite a few people out there just looking for somewhere to use Haskell! :) And in fact, there have also been developers who learned Haskell expressly for the purpose of contributing to darcs. It's such a pleasant language to work with that I think it's more of a draw to developers than a put-off.

So perhaps you should attempt to assimilate some facts before trotting out your tedious, ill-informed prejudices, hmmm?

Furthermore, it's not just about the sheer number of developers, it's about the power of the language. A million monkeys writing code are still only monkeys, and the more developers you have on a project, the more co-ordination is required (read Fred Brooks' The Mythical Man-Month if you don't believe me).

If "number of potential developers" were the only criterion for choosing a project's programming language, everything would be written in BASIC. And Paul Graham makes a good case [paulgraham.com] for coding in less common languages: you'll get people smart enough to learn unusual languages for the hell of it, rather than a mass of monkeys who have little interest in building great software and just want to learn this week's marketable language to improve their employment prospects.

Re:Haskell just won't cut it (3, Insightful)

Mr. Slippery (47854) | more than 9 years ago | (#10916441)

Why on earth would the users of a piece of software care about the language it's written in?

If your users are FOSS developers, they quite likely care about the ability to modify the tool, which includes caring about the languate in which it is written.

Re:Haskell just won't cut it (3, Interesting)

pnot (96038) | more than 9 years ago | (#10916507)

me: Why on earth would the users of a piece of software care about the language it's written in?

you: If your users are FOSS developers, they quite likely care about the ability to modify the tool, which includes caring about the languate in which it is written.

Interesting point. Certainly FOSS developers care about being legally allowed to modify code, but I'm not sure that they care, on the whole, about the language.

emacs, for example, is largely written in elisp -- hardly a mainstream language. Yet it's extremely popular, even among people who don't know any lisp. People who find the need to extend it get a good excuse to learn lisp in a well-motivated, incremental way.

Speaking personally, I'd be ''more'' inclined to hack on a project written in something interesting like Haskell, ML, Smalltalk, or Lisp. (In fact I chose my current main project partly as an excuse to learn Lisp.) A lot of people like having a motivation for learning a new language, or a practical use for an "academic" language they happen to know. (I learned Haskell in university, so I'd be quite keen to get to use it in the "real world".)

I think the only time I'd care about the language of a program I'm using would be if it were written in something particularly horrible -- "urgh, if I ever want to modify this I'll have to learn befunge!" But perhaps that's the way some people view Haskell ;-).

It's a matter of taste, I suppose. I do acknowledge that I'm a bit of a language nut.

I still maintain that quality is more important than quantity, though. I've been teaching C and Java to second-year undergraduates this year -- having seen some of their code, I can safely say that if I were starting an OSS project, I'd rather have one seasoned Haskell hacker on board than the entire lot of 'em :-).

Re:Haskell just won't cut it (1)

pnot (96038) | more than 9 years ago | (#10916517)

I wrote: I'd be ''more'' inclined...

Ugh. I meant: I'd be more inclined...

Sorry. Too much time on Wikipedia.

Re:Haskell just won't cut it (1)

Earlybird (56426) | more than 9 years ago | (#10916365)

  • While "Darcs is written in a Haskell, a functional language that is relatively unknown compared to C or Perl", this really does hurt it's common use.
I call bullshit. First, the language that a product is written in doesn't hurt use -- it only affects the development process.

Secondly, what's in a language? I didn't know Haskell until I started looking at Darcs; now I know a bit of Haskell, and soon I hope to be proficient enough to contribute.

There's something to be said for language agnosticism. Haskell is a fine -- even brilliant -- language. The code is there, it's readable for anyone with half a brain.

In the end, the fact that Darcs is written in Haskell will not stop most people from being interested in developing it. Or at least, not the people you'd want to contribute; it's a nice prejudice filter.

  • A community project will ultimately be the versioning system for community projects.

That sentence does not make sense. Are you saying the same people who use a version control system should also develop it? I'm sure you will find that most CVS users have never seen even a line of the CVS source code.

Re:Haskell just won't cut it (1)

user9918277462 (834092) | more than 9 years ago | (#10916403)

Remember when Arch was first being bandied about? Tom Lord made a big deal about how writing it as a bunch of shell scripts (err, "POSIX standard SH" not bash) was actually a good idea and helped speed development and didn't really hurt performance, etc. Guess what? No one used arch because as sound as the theory behind it might be, as concrete software it seemed like a joke.

So someone came along and did the hard work of reimplementing it in a real language and suddenly the world is taking Arch seriously. I wouldn't be surprised if we end up seeing a similar situation pan out with Darcs.

Re:Haskell just won't cut it (0)

Anonymous Coward | more than 9 years ago | (#10916689)

Are comparing Haskell to "shell scripts" and saying that Haskell is not a real programming language?

That is like comparing smut to Michelangelo's David.

Re:Haskell just won't cut it (0)

Anonymous Coward | more than 9 years ago | (#10917094)

The only reason that Haskell will hurt the adoption of Darcs is the fact that it doesn't have particularly good platform support.

While writing a program in a non-mainstream language will cause contributors to be selected from a smaller pool of people, that set of potential contributors will probably be better programmers (knowing and understanding more programming languages and techniques makes people better programmers).

it cuts it just fine (1)

jeif1k (809151) | more than 9 years ago | (#10917099)

Lots of people know how to program in C or Perl to some degree, but you wouldn't want most of them modifying the version control system you are relying on. The pool of capable C or Perl programmer is actually much smaller. And even inexperienced Haskell programmers can do considerably less damage modifying Haskell code than they could modifying C or Perl code.

Furthermore, darcs doesn't need a "large group of developers", both because it's not a huge system and because it's written in Haskell. Being written in Haskell probably makes it an order of magnitude smaller and easier to maintain.

Decentralization (0)

eeg3 (785382) | more than 9 years ago | (#10916172)

The idea of decentralizing CVS is, indeed, a humongous deal. While, David's Advanced Revision Control System sound quite silly... it's a really great alternative. I'd like to see it implemented everywhere, although CVS is still better in some instances.

Re:Decentralization (2, Insightful)

cduffy (652) | more than 9 years ago | (#10916322)

Mighty vague, that. What instances is CVS better in?

Compared to modern revision control systems, I don't think CVS is even in the running. It's SVN (in the non-distributed camp), and Arch, Darcs and Monotone in the distributed camp... with plenty of infighting between them.

Re:Decentralization (1)

Gopal.V (532678) | more than 9 years ago | (#10916569)

> What instances is CVS better in?

When you need symlinks in the repository . When all you have for backup is a solaris machine with a tape drive , When you need a web interface to update password ... It has its Niche .

That said , I just love how easily you can setup a darcs repository (just like cvs)

Re:Decentralization (1)

eloki (29152) | more than 9 years ago | (#10917164)

> When you need symlinks in the repository.

Um, I don't know what you're referring to, CVS ignores symlinks in checkouts. Maybe you meant symlinks literally in the repository itself, but I'm struggling to see a scenario where that is important and symlinks would simply be a workaround to the real problem.

Darcs is KISS (5, Informative)

Earlybird (56426) | more than 9 years ago | (#10916335)

Among the plethora of emerging version control systems [zooko.com] -- Subversion, Arch, Monotone and so on -- Darcs stands out for its simplicity and thoughtful design.

Like CVS, you can get productive within minutes; the same cannot be said for Arch or even Subversion. Let's see:

john@somewhere$ cd ~/myproject
john@somewhere$ darcs init
You now have a Darcs repository! Let's do something with it:
john@somewhere$ darcs add -r *
john@somewhere$ darcs record -am "Initial import."
Finished recording patch 'Initial import.'
Now your repository contains all your files. Let's look at the changelog:
john@somewhere$ darcs changes
Thu Nov 25 06:26:19 CET 2004 johndoe@example.com
* Initial import.
Now, where's the server? You need a server to share your repository, right? Nearly -- every repository is a potential server, as long as it's accessible either through the file system, through SSH/SFTP, HTTP or email. Let's go to another machine and check out the repository we just made:
jane@elsewhere$ darcs get john@somewhere:~/myproject
Copying patches...
.
Finished getting.
We now have a repository on Jane's box. Let's make a modification:
jane@elsewhere$ echo "#include <foo.h>" >>foo.c
jane@elsewhere$ darcs whatsnew --summary
M ./foo.c +1
jane@elsewhere$ darcs whatsnew
{
hunk ./foo.c 2
+#include <foo.h>
}
This last output, by the way, is Darcs' patch format. A "hunk" is a line-based diff. Other types of changes that may be contained in a changeset include renames, moves and binary changes. (Yes, you can also get a GNU-patch-compatible output similar to "cvs diff".)

Now let's commit and push the changes back to John's repository:

jane@elsewhere$ darcs record -am "Added a missing include."
jane@elsewhere$ darcs push -a
[...]
Finished applying...
Now we can go back to John's machine and look:
john@somewhere$ darcs changes
Thu Nov 25 06:26:10 CET 2004 janedoe@example.com
* Added missing include.

Thu Nov 25 06:26:19 CET 2004 johndoe@example.com
* Initial import.
(Note how Darcs generates a GNU-style changelog for you automatically.)

Where are the revision numbers, you ask? Well, they don't exist, because they're not needed. Darcs is changeset-oriented, not file-oriented. You can refer to a changeset by name, date, or a special hash identity.

Darcs changesets aren't just GNU patches; they have context, which means, for example, that someone can check out a repository, move a file "foo.c" into the directory "bar" and commit; meanwhile, another person, working on an older copy of the same repository, edits foo.c (which is still in its old location) and commits that. Darcs know that this edit should apply to foo.c in the new location -- and unlike CVS, you don't need to do anything similar to "cvs update" if you're committing files that have been changed on the server. In other words, people can freely commit changes, and the only kind of visible "conflict" will occur when you actually edit the exact same line.

Unlike CVS and Subversion, but like Arch and Monotone, Darcs is a distributed version control system. Repositories are islands which are constantly out of sync with each other, and Darcs' patch commutation system takes care of integration the changes that flow between them.

This system has several extremely useful effects:

  • Offline mode [sourcefrog.net]. You can commit changes even if you're on the road with no access to the server. That's because your own working directory is a repository in its own right. When you get home, you do a "darcs push" to commit to the public server.
  • Easy branching. Every repository is a branch. Working on implementing some feature but need to fix a bug? You don't want to check in your work in progress just to check in a bugfix, so you branch off the trunk and work on the fix.
  • Linus mode. I want to add a feature or bugfix to an open-source project. I make a local Darcs copy, apply my changes, then send my changes by email ("darcs send"). The project's maintainer(s) can decide whether to accept or reject the changes. This way, you don't necessarily need to screw around with commit privileges. This is how Darcs itself is maintained, by the way. This is also similar to the way Linux is/was maintained, except the process is implemented in software.
  • Parallel development. Let's say I follow the development of this open-source project, and I have some "controversial" patches that aren't accepted by the official maintainers. No problem -- I make my changes, release my own distribution. It's a fork, of sorts, but it's still connected to the mainline. Whenever the official project makes changes, I do a "darcs pull" to get them, and resolve any conflicts. This way, my fork is kept up to date with the main project's repository.
  • Easy local revision control. CVS/RCS is popular for versioning home directories, /etc, etc. With Darcs you get the simplicity of RCS with the power of, well, Darcs. Maintaining the same config on a myriad of PCs becomes easier, not least because Darcs supports pushing of changes; I can make changes and push them to all my servers with a single command.
  • Cherrypicking. If you've ever worked on a team, you will know that somebody often has a change you wan, but which can't be committed to the trunk yet. With Darcs you can grab just the one change by pulling it into your repository.
Is Darcs perfect? No. The current implementation has some performance/scalability issues with really large repositories [darcs.net]. However, this is being actively worked on.

Re:Darcs is KISS (2, Interesting)

mindstrm (20013) | more than 9 years ago | (#10916451)

Some nice features there... but you open up with saying "Like CVS, you can get productive within minutes; the same cannot be said for Arch or even Subversion."

Subversion:

# Create a local respitory & add files.

svnadmin create /path/to/repository
svn import * file://path/to/repository

I'm really not quite sure how that qualifies as "can't be set up in minutes". Easily as fast as darcs, and very simple.

The distributed features are what make darcs unique.. it doesn't seem to me to be any fundamentally easier or faster for basic revision control than subversion, though.

Re:Darcs is KISS (1)

Earlybird (56426) | more than 9 years ago | (#10916470)

  • The distributed features are what make darcs unique.. it doesn't seem to me to be any fundamentally easier or faster for basic revision control than subversion, though.

Subversion seems similarly easy to get started with, but what about repository sharing? To let other people access your repository, you must set up a server of some kind, be it WebDAV, or svnserve -- although I'm sure Subversion must support something like an "ssh://" protocol.

Re:Darcs is KISS (1)

Koguma (608998) | more than 9 years ago | (#10916574)

Subversion runs through Apache/2, so if you've got ssl setup in Apache, you have SSL on your repository. What I really love about Subversion is that it grabs the Apache authenticated user and uses that as the repository user. Once you set it up, it's really neat, and you get fine grained control. Setting up the repository is quick, but setting up acl's to it is trickier. Still with WebSVN and other tools, it's really sweet.

Re:Darcs is KISS (2, Informative)

Earlybird (56426) | more than 9 years ago | (#10916814)

  • Subversion runs through Apache/2, so if you've got ssl setup in Apache, you have SSL on your repository ...

Sorry, but we were talking about simplicity here. Apache 2.0, SSL, authentication, WebDAV... Setting up a repository with what you suggest is more than one step -- it's usually a lot of steps, especially considering Subversion's external dependencies.

Setting up a Darcs repository consists of doing this:

$ darcs init

And Darcs works over SSH:

$ darcs get bob@example.com:/some/project

This gives you security (leveraging the public-key encryption system of OpenSSH) without having to set up Apache, SSL, virtual hosts, WebDAV or authentication.

You can also use Darcs read-only over HTTP (the following will check out the Darcs sources):

$ darcs get http://www.abridgegame.org/repos/darcs/

All that's required is a web server mapping the URL to your repository -- any one will do.

I'm sure Subversion works similarly, though.

Re:Darcs is KISS (2, Informative)

o1d5ch001 (648087) | more than 9 years ago | (#10917647)

You can run Subversion using the svnserve tool as well. To start the server:

svnserve -d -c /repo

To access it:

svn co svn://somehostname

or with ssh

svn co svn+ssh://somehostname

Re:Darcs is KISS (2)

jbert (5149) | more than 9 years ago | (#10916811)

Yup.
svn co svn+ssh://user@host/path/to/repo repo
will check out a repository, tunnelled over ssh. No need to run a subversion server to do that.

One of the nice things about subversion (recently converted user, very happy so far) is the support for multiple url formats and communications methods.

Another notable thing (for windows users) is TortoiseSVN, (an explorer shell extension) which is just great.

I can see how the distributed, multi-repo model of bitkeeper/darcs/arch is superior but svn looks good if you only need single-repo.

Also, bitkeeper has some powerful gui tools (and probably the kitchen sink too). Haven't really used arch/darcs.

Re:Darcs is KISS (4, Interesting)

Earlybird (56426) | more than 9 years ago | (#10916845)

  • One of the nice things about subversion (recently converted user, very happy so far) is the support for multiple url formats and communications methods.

Darcs and Arch both have this. (Arch undoubtedly has the most extensive protocol support of any revision control system.)

  • Another notable thing (for windows users) is TortoiseSVN, (an explorer shell extension) which is just great.

Tortoise is quite nice indeed -- I used TortoiseCVS for years.

  • I can see how the distributed, multi-repo model of bitkeeper/darcs/arch is superior but svn looks good if you only need single-repo.

Need is just one aspect of the development process; right now CVS gives most people what they need, despite the cracks in the lacquer. Darcs doesn't just erase the cracks, but improves the process.

For example, I occasionally submit patches to certain open-source projects. The easiest way to do this is to check out the CVS repository, make my changes, and do "cvs diff -u" to get the patches in that format, which I tend post to some Bugzilla server or email to somebody. But I can't commit them. I don't mean to the master repository -- I mean locally. There's no way I can bundle my file patches in a changeset and keep its history. I'm basically managing a CVS working directory where my changes are never checked in.

With Darcs, I just do "darcs get" to get the master repository, make my changes, commit them locally. I can use "darcs send" to submit my changes to the project maintainer. Anyone else can grab my patches with "darcs get" or "darcs pull". I can be Alan Cox to some Linus without breaking my back over patch management.

Re:Darcs is KISS (1)

David Roundy (34889) | more than 9 years ago | (#10917636)

Darcs and Arch both have this. (Arch undoubtedly has the most extensive protocol support of any revision control system.)

Although Arch does have extensive protocol support, I'm not sure it's up to par with darcs, since I think it's missing support for some obscure protocols such as http and gopher.

Re:Darcs is KISS (1)

Vintermann (400722) | more than 9 years ago | (#10916929)

"The distributed features are what make darcs unique.."

Hardly, as it is the defining feature of BitKeeper and GNU Arch. It's a very good idea, however.

Re:Darcs is KISS (1)

DrEasy (559739) | more than 9 years ago | (#10916815)

Wow... This looks so much simpler even than CVS, especially as soon as things get hairy with parallel development.

Perfect sales pitch! I'll have to "check it out" now, guess I should say "whatsnew it" instead! :)

Re:Darcs is KISS (1)

boa13 (548222) | more than 9 years ago | (#10916873)

Your comment would still be correct if I changed every occurence of "darcs" with "arch" (except for the command lines, of course).

So, what's the difference between Arch and Darcs?

Here: (2, Informative)

warrax_666 (144623) | more than 9 years ago | (#10917063)

I think you may find this page [berlios.de] interesting.

Major differences:
  1. Darcs is must less strict: For example, it doesn't have a built-in concept of branches/versions (which is necessary in Arch because of the patch ordering/application constraints).
  2. All working directories are repositories themselves. This can be very useful (for example, it makes it trivial to manage /etc using darcs), but also somewhat dangerous.
  3. Interactive approval of every recorded diff chunk (change). This may not sound like a big deal, but if you have spurious changes in a tree which you'd rather not record(*) in a given changeset, interactive prompting makes it a a lot easier to achieve clean changesets which only touch one "aspect" of the source at a time.


(*) Such as typo fixes, comment fixes, etc. which you just happened to notice while fixing a particular bug.

Re:Here: (1)

bani (467531) | more than 9 years ago | (#10917131)

going by that page, subversion looks like a better deal than darcs.

Re:Here: (0)

Anonymous Coward | more than 9 years ago | (#10917163)

going by that page, subversion looks like a better deal than darcs.

I fail to see that.

Huh? (1)

warrax_666 (144623) | more than 9 years ago | (#10917295)

I fail to see how. It isn't strictly superior in all categories, and there are certainly some significant differences which would make either (but not both) viable in certain scenarios.

Disclaimer: I'm currently using Arch for all my repos, but that's mainly because Haskell is not really supported properly on my architecture (by my distro). Yet.

Re:Here: (3, Interesting)

boa13 (548222) | more than 9 years ago | (#10917190)

One important feature is missing from the page:

Support for signing patches and archives

Allows to verify who created/commited the patches. Allows to verify the integrity of a repository in case of compromise.

* Arch: Excellent. Each patch can be signed, repositories can be fully verified.
* Darcs: Incomplete. Patches sent by email can be signed so the recipient can verify the identity of the submitter. No support for verifying repository integrity. [1]
* Subversion: N/A

[1] Problem is: You can only sign something that will not vary once distributed, Darcs patches vary once distributed.

Mostly agreed, but (1)

warrax_666 (144623) | more than 9 years ago | (#10917324)

I suspect your footnote is incorrect (although it been a long time since I looked at darcs and may remember incorrectly). IIRC, the patches themselves don't vary once distributed, just the ordering of them, so it should be possible to sign individual changes. Of course, this isn't nearly enough to verify repository integrity/authenticity, but I think something could be added relatively easily.

Re:Mostly agreed, but (1)

evvk (247017) | more than 9 years ago | (#10917557)

Patches themselves do vary at least when a merger patch is needed (conflict). But this could be stored as a patch to the patch. It might even be possible to verify that the stored changes are correct.

Re:Mostly agreed, but (2, Informative)

David Roundy (34889) | more than 9 years ago | (#10917600)

No, I'm afraid the footnote is dead on. When patches are commuted their content changes, although their meaning remains the same. This happens when people pull (or push) patches from one repository to another.

There is an idea, a repository of patch bundles, which could allow signed patches to be kept, at the cost of either duplication of information or inefficiency. It would "just need to be implemented." It would be a bit tedious, but is simple enough that it could be done (terribly inefficiently) using external scripts.

Re:Darcs is KISS (1)

grumbel (592662) | more than 9 years ago | (#10917224)

The only problem with Arch is that while the implementation might be KISS, the user interface is not and its almost impossible to map a good old CVS-users workflow onto Arch.

Its the clients and API that matter (3, Informative)

monkeyboy87 (619098) | more than 9 years ago | (#10916456)

no matter what the change set "theory" are implemented into the product if it's not easy to do things with it, it will languish. VSS and CVS are still used widely becuase there are lots of clients and tools that make it useful. the draw of SVN (loved or hated) is that it has a good client and the command line client is easy to drive with scripting tools

Interesting app. non-troll questions (2, Interesting)

mattr (78516) | more than 9 years ago | (#10916466)

The previous poster who showed how easy it is to use darcs sold me, I am thinking it could be real useful
right away just for my own work.

Took a brief look at the pretty site. Personally I've been intrigued by Haskell for a while though never jumped in, and I use Perl. My questions:

1. Can the elegant quantum reality inspired code be separated off? Though my take is that it is already separate, as a Haskell function.. the reason for the question is that it sounds like it would be useful for a whole lot of things. Instead of implementing app/protocol X over darcs, I am wondering if you could include an (inline) Haskell module in a Perl app that would do the rest.

1.5 ..or is there another way to access the Haskell theory of patches functionality from outside the app?

2. Next question, can Haskell be embedded inline in Perl code?

3. Can the quantum theory of patches be implemented as a Perl module, and ignoring the probably truth that anything not Haskell will not be as elegant as Haskell, would such an implementation benefit/be renedered possible by using the Perl functional or Quantum:: modules?

3.5 At risk of a flame war I'd love to use this in XEmacs. Anybody? This post written in vim so no flames please!

4. Reading about the symmetry or lack of it, concepts of physics this is helping me think about an app of my own. I'd like to read more about this does anyone have links?

5. Time to learn Haskell!! Great!

Re:Interesting app. non-troll questions (2, Interesting)

Earlybird (56426) | more than 9 years ago | (#10916508)

I can't answer all of your questions. The mailing list [abridgegame.org] would be the place to ask.

  • 2. Next question, can Haskell be embedded inline in Perl code?

Not that I'm aware. However, all you need is an embeddable Haskell interpreter. I believe this is possible with Hugs [haskell.org], which has a "server interface [haskell.org]", and possibly even with ghc [haskell.org] (the native compiler that Darcs is compiled with). You'd probably have to write the C/Perl interface yourself.

  • 3. Can the quantum theory of patches be implemented as a Perl module ...

Certainly.

  • 4. Reading about the symmetry or lack of it, concepts of physics this is helping me think about an app of my own. I'd like to read more about this does anyone have links?

More than anything it's mathematics. But David Roundy, the author of Darcs, is a physicist, and may have some pointers for you.

  • 5. Time to learn Haskell!! Great!

If you're a Perl hacker, you might be interested in this [gla.ac.uk]. Scary, eh?

Re:Interesting app. non-troll questions (5, Informative)

David Roundy (34889) | more than 9 years ago | (#10917486)

1. It's actually hard to use the patch commutation code to do any good outside the concept of a darcs repository.

1.5 I've thought about creating a C library for manipulating/querying darcs repositories, but haven't gotten around to it. The hard part would be of course designing the API. Ideally I'd like the interface to be such that programs using the library couldn't accidentally corrupt the repository.

2. Darcs requires ghc, since it uses some library code only available in ghc to do more efficient IO, string manipulation and to access zlib. It turns out to be a pain on many systems to link with the necesary libaries when using the interpereted version of ghc. So probably accessing darcs from perl will have to go through the executable until a C library is written (which could of course have perl bindings).

3. Rewriting darcs in perl (or parts of it) would be possible, but would be a pain. In particular, the commutation of patches which have conflicts is pretty complicated.

This crap is news? (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#10916475)

Bloody bunch of no-life nerds why don't you's go and get some pussy instead of reading this shite?

Theory of patches (0, Troll)

geneing (756949) | more than 9 years ago | (#10916480)

Let me summarize the "theory of patches": you reverse patches in the opposit order of applying them.

I don't know why anyone would make a big deal out of that.

I have to agree with many other comments: the use of haskell eliminated it as a choice for me. I use subversion instead, and still looking for a better vcs. I checked all the available free (and some non-free) systems and all of them have major warts.

Re:Theory of patches (1)

Animats (122034) | more than 9 years ago | (#10916489)

And what do you do when you merge together two divergent versions? That's what patch theory is all about.

Re:Theory of patches (1, Insightful)

Anonymous Coward | more than 9 years ago | (#10916524)

> the use of haskell eliminated it as a choice for me. I use
> subversion instead,

So... How many times have you made local modifications to Subversion, and how many patches have you submitted?

Which language is Subversion coded in ...without looking it up?

Thanks.

Re:Theory of patches (3, Insightful)

Earlybird (56426) | more than 9 years ago | (#10916700)

  • Let me summarize the "theory of patches": you reverse patches in the opposit order of applying them.

No. Darcs can, and will, apply patches out of order. From the Darcs manual [abridgegame.org]:

  • The development of a simplified theory of patches is what originally motivated me to create darcs. This patch formalism means that darcs patches have a set of properties, which make possible manipulations that couldn't be done in other revision control systems. First, every patch is invertible. Secondly, sequential patches (i.e. patches that are created in sequence, one after the other) can be reordered, although this reordering can fail, which means the second patch is dependent on the first. Thirdly, patches which are in parallel (i.e. both patches were created by modifying identical trees) can be merged, and the result of a set of merges is independent of the order in which the merges are performed. This last property is critical to darcs' philosophy, as it means that a particular version of a source tree is fully defined by the list of patches that are in it, i.e. there is no issue regarding the order in which merges are performed.

A distributed version control system that required all patches to be applied in order would be painful indeed to use.

  • I have to agree with many other comments: the use of haskell eliminated it as a choice for me.

Why? Are you a Subversion contributor?

Re:Theory of patches (2, Funny)

IrvineHosting (628102) | more than 9 years ago | (#10916774)

Wow, that actually sounds really cool! I just be happy if I could get my SourceSafe repository to stop corrupting.

Re:Theory of patches (1)

Deusy (455433) | more than 9 years ago | (#10917474)

"I have to agree with many other comments: the use of haskell eliminated it as a choice for me. I use subversion instead, and still looking for a better vcs. I checked all the available free (and some non-free) systems and all of them have major warts."

Why did it being in Haskell eliminate it as a choice? What kind of anal reason is that? Surely it's irrelevant what language anything is written in, insetad what matters is how good the program is. Or do you eliminate Haskell-based apps because you are a doting user who commits bug fixes back to projects? I doubt it.

The theory of patches [abridgegame.org] is also more complex than you make it out to be. You only describe one of the simpler facets of the theory.

Needs wider adoption (4, Interesting)

haeger (85819) | more than 9 years ago | (#10916514)

While darcs is nice it needs wider adoption. When it comes to a project that people are working on, you have almost as many boxes as you have developers and for a revision control program to be adopted and used there has to be binaries for all those devels. AFAIR there are some issues with the win32 binary? One of our devels had major problems with it and now we're living with both a cvs and a darcs repository, and noone really knows where to send patches. I think it's safe to say that our project is dying, if not dead already.

Not that I blame darcs or anything, just that one need to be sure that darcs work for everyone before commiting to it. CVS works on all platforms and is well tested. Darcs will hopefully get there.

And yes, I did my part and created a package for my platform. It's linked from the binary download page.

.haeger

Re:Needs wider adoption (2, Insightful)

Anonymous Coward | more than 9 years ago | (#10916831)

CVS works on all platforms
... for an appropriate definition of "works".

CVS doesn't have atomic check-in, it's directory handling is crap, etc. etc. Still, like you said, it's probably still the best bet if you want to do development on both UNIX and Win32, although Subversion(!) is catching up fast.

Re:Needs wider adoption (1)

OldMiner (589872) | more than 9 years ago | (#10917418)

One of our devels had major problems with it and now we're living with both a cvs and a darcs repository, and noone really knows where to send patches. I think it's safe to say that our project is dying, if not dead already.

Isn't the problem that you didn't make a firm commitment one way or another at that juncture? You had the option of either going all darcs or all CVS. It seems like instead of confronting the issue at the time, you let your project self destruct.

You could have chosen to switch to CVS and accepted losing the features of darcs.

You could have set an ultimatum for that developer. It's a small project, and you can't afford to be split. Most large projects can't. Offer a Knoppix CD, a shell account somewhere, to take patch files, or help getting the Windows binary working. Or give them the option of developing a fork on their own. I find it unlikely your developer would have left, and even if she had, your project might be better off for the lack of division. Meanwhile, a bug report might get the Win32 port fixed [google.com]. But what was broken with it exactly which made it so bad?

Naturally, I don't know the details, so pardon me if darcs ate your developer's favorite president and she was sworn to revenge. But, it doesn't sound like the current state of events is very positive either.

Choose the development tool you prefer (2, Insightful)

curne (133623) | more than 9 years ago | (#10916801)

It seems to me that a LOT of people in these comments are remarking that David's choice of Haskell makes darcs a no-go. I would make this comment:

If someone told you to use <Tool X> for a project, you would say, "No way, <Tool Y> is more suitable for this job, and it's what I want to use." (substitute X and Y with whatever - C/Java/Perl/VB - you want).

I think David chose what he felt was the best tool for the job, taking the problem-to-solve and his own expertise into consideration. In the light of Paul Graham's insights [paulgraham.com] I really think he should be applauded rather than criticised.

decentralize CVS? (1)

Skadet (528657) | more than 9 years ago | (#10916855)

Decentralize CVS? I have a hard enough time getting to the cash registers as it is, dammit!

Our experience CVS vs. DARCs (4, Informative)

ites (600337) | more than 9 years ago | (#10917081)

We are looking at something to replace our ageing CVS system. We have large OSS projects, worked on by teams of 3-10 people. CVS is very good for what it does but we are feeling its limitations. The biggest problems are that forks are too delicate to use, so we don't use them, and that in order to work you need access to the central archive.

Darcs looked like the best choice. We converted and imported some of our archives. Then we tried checking them out. With CVS, 2-3 minutes. With darcs, 30 minutes.

Our conclusion: darcs is not scalable. Admittedly our code base is large and has a huge history, but in order to use darcs we would have had to break our projects into many small pieces, each with their own repository.

Darcs looks good. But it needs to be made much, much faster if it's to work with large projects.

If you're currently using CVS... (2, Interesting)

Phil John (576633) | more than 9 years ago | (#10917105)

...why not make the jump to a system meant to replace CVS's centralized model, such as subversion. Forks are very easy to do, truly atomic commits, CVS to SVN repository converter, similar command line params to CVS etc. etc.

Our current repo is 9 gigs and works beautifully.

Re:Our experience CVS vs. DARCs (1)

eloki (29152) | more than 9 years ago | (#10917226)

> Our conclusion: darcs is not scalable.

Um, isn't that basically in the article? In fact, when you read about darcs this caveat is described everywhere - the manual, webpages comparing OSS version control systems, posts I've seen about darcs on LWN, here on /. etc... A good investigation would have tipped you off to this fact before you started.

Re:Our experience CVS vs. DARCs (1)

master_p (608214) | more than 9 years ago | (#10917347)

Is it because Haskell is an interpeted language, or it is a design fault? I doubt it is the language, but I thought to cover that base too.

Re:Our experience CVS vs. DARCs (5, Informative)

David Roundy (34889) | more than 9 years ago | (#10917441)

Darcs get (equivalent to CVS checkout) is the single least efficient command in darcs. People keep telling me I need to fix this, since it's the first thing users see, but it's really not an important command to optimize (apart from first impressions issues). When run locally (to create a new branch) it's fast.

And comparing darcs get with cvs checkout really isn't fair, since darcs gives you a copy of the full history of the repository, a separate branch on which to record changes before committing them to the centralized repository, and the ability to browse the history offline.

If you want a fast get, just run optimize --checkpoint on the parent repository (assuming you've tagged recently--if not, then tag the current state first), and then use the --partial flag when running darcs get. It'll still give you more flexibility than a cvs checkout, and will be much faster.

Linus opinion (1, Interesting)

Anonymous Coward | more than 9 years ago | (#10917241)

Do you see Darcs as a viable version control system for the Linux kernel?

How do you view Linus opinion on version control systems?

Darcs vs Svn (-1, Troll)

kahei (466208) | more than 9 years ago | (#10917570)


Getting started with subversion:

Create. Import. Update. Commit.

Getting started with Darcs:

Install your first ever copy of Haskell, and begin to learn the 'theory of patches'...

This is a problem domain that seems to attract elegant, clever solutions that don't pay much attention to usability. Svn has been (partly) an exception to this -- it focuses on delivering simple, obvious functionality in a convenient way (now that that silly BerkelyDB and DAV stuff is fading away). To me, I must say this makes Svn a far more promising project than Darcs or Arch.

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