Re: RFC: migrating to git

2011-02-01 Thread Lars Viklund
On Mon, Jan 10, 2011 at 11:19:23AM +, Simon Marlow wrote: > It's time to consider again whether we should migrate GHC development > from darcs to (probably) git. The Boost project has been having similar discussions about when, how and if to migrate to Git, together with discussions on wheth

Re: RFC: migrating to git

2011-01-25 Thread Max Bolingbroke
On 25 January 2011 09:35, Lars Viklund wrote: > A subtree seems to be a way of getting the > contents of a branch merged at a non-root location. It might be a > relevant read and something to evaluate. There is also the git-subtree project (https://github.com/apenwarr/git-subtree). They explain t

Re: RFC: migrating to git

2011-01-25 Thread Lars Viklund
On Mon, Jan 10, 2011 at 06:22:03PM -0600, David Peixotto wrote: > Another possible advantage to git would be its support for submodules[1]. If > we made the switch to git for all the repositories that GHC uses, then we > could set them up as submodules. The advantage of submodules is that the GHC

Re: RFC: migrating to git

2011-01-17 Thread Simon Marlow
On 17/01/2011 14:08, r...@cse.unsw.edu.au wrote: On Mon, January 17, 2011 11:08 pm, Simon Marlow wrote: So, we've decided to try switching to git. That's very sad! The changeover will be staged: first we'll switch the GHC repository, and if all goes well we'll switch the libraries and other

Re: RFC: migrating to git

2011-01-17 Thread rl
On Mon, January 17, 2011 11:08 pm, Simon Marlow wrote: > > So, we've decided to try switching to git. That's very sad! > The changeover will be > staged: first we'll switch the GHC repository, and if all goes well > we'll switch the libraries and other sub-repositories. This means we can > exper

Re: RFC: migrating to git

2011-01-17 Thread Simon Marlow
Thanks to everyone who responded on this thread! It's great to see so much feedback. Of the people who responded, most were in favour of a switch to git, with a few notable exceptions. Here at GHC HQ, I'm slightly in favour of switching while Ian and Simon PJ are agnostic. So, we've decided

Re: RFC: migrating to git

2011-01-14 Thread Simon Marlow
On 13/01/2011 19:11, Brian Bloniarz wrote: On 01/13/2011 12:49 AM, Simon Marlow wrote: I spent quite some time yesterday playing with submodules to see if they would work for GHC. I'm fairly sure there are no fundamental reasons that we couldn't use them, but there are enough gotchas to put me

Re: RFC: migrating to git

2011-01-13 Thread Brian Bloniarz
On 01/13/2011 12:49 AM, Simon Marlow wrote: > I spent quite some time yesterday playing with submodules to see if they > would work for GHC. I'm fairly sure there are no fundamental reasons that > we couldn't use them, but there are enough gotchas to put me off. I wrote > down what I discovered he

Re: RFC: migrating to git

2011-01-13 Thread Max Bolingbroke
On 12 January 2011 22:13, Claus Reinke wrote: >> You can emulate darcs's patch re-ordering in git if you put each >> independent sequence of patches on a separate branch. Then you can >> re-merge the branches in whatever order you want. This is a fairly >> common git workflow. > > What happens aft

Re: git repos for testing (was: Re: RFC: migrating to git)

2011-01-13 Thread Johan Tibell
On Thu, Jan 13, 2011 at 4:03 PM, Simon Marlow wrote: > I've made git mirrors of the current GHC HEAD repos (all of them), so people > can try out their workflows with git. Poking around in the different repos works for me and is fast. For example: Find new files in base: $ cd libraries/base $ g

git repos for testing (was: Re: RFC: migrating to git)

2011-01-13 Thread Simon Marlow
I've made git mirrors of the current GHC HEAD repos (all of them), so people can try out their workflows with git. Hopefully this should work: git clone http://darcs.haskell.org/ghc-git/ghc.git cd ghc perl sync-all get You have to use sync-all instead of darcs-all, but the syntax is the

Re: RFC: migrating to git

2011-01-13 Thread Thomas Schilling
On 13 January 2011 08:54, Roman Leshchinskiy wrote: > On 12 Jan 2011, at 23:31, "Edward Z. Yang" wrote: > >> Excerpts from Roman Leshchinskiy's message of Wed Jan 12 18:20:25 -0500 2011: >>> How would we get the current functionality of darcs-all pull? Is it even >>> possible? >> >> Here is the

Re: RFC: migrating to git

2011-01-13 Thread Roman Leshchinskiy
On 12 Jan 2011, at 23:31, "Edward Z. Yang" wrote: > Excerpts from Roman Leshchinskiy's message of Wed Jan 12 18:20:25 -0500 2011: >> How would we get the current functionality of darcs-all pull? Is it even >> possible? > > Here is the rebase-y workflow. Thank you making things clearer! >> >

Re: RFC: migrating to git

2011-01-13 Thread Simon Marlow
On 12/01/2011 22:22, Iavor Diatchki wrote: Hello, On Wed, Jan 12, 2011 at 11:44 AM, Roman Leshchinskiy mailto:r...@cse.unsw.edu.au>> wrote: On 12/01/2011, at 09:22, Simon Marlow wrote: > On 11/01/2011 23:11, Roman Leshchinskiy wrote: >> >> A quick look at the docs seems to i

Re: RFC: migrating to git

2011-01-12 Thread Edward Z. Yang
Excerpts from Roman Leshchinskiy's message of Wed Jan 12 18:20:25 -0500 2011: > How would we get the current functionality of darcs-all pull? Is it even > possible? Here is the rebase-y workflow. Untested, so I might have gotten one or two details wrong. > Suppose I want to hack on GHC and base

Re: RFC: migrating to git

2011-01-12 Thread Roman Leshchinskiy
On 12/01/2011, at 22:22, Iavor Diatchki wrote: > When you issue the command "git submodule update", you are telling git to > advance the sub-module repo to the "expected version" (i.e., where the > pointer points to). The reason this does not happen automatically is that > you might have also

Re: RFC: migrating to git

2011-01-12 Thread Tim Chevalier
On Mon, Jan 10, 2011 at 8:52 AM, Malcolm Wallace wrote: > As another non-GHC contributor, my opinion should probably also count for > little, but my experience with git has been poor. > > I have used git daily in my job for the last year.  Like Simon PJ, I > struggle to understand the underlying m

Re: RFC: migrating to git

2011-01-12 Thread Claus Reinke
You can emulate darcs's patch re-ordering in git if you put each independent sequence of patches on a separate branch. Then you can re-merge the branches in whatever order you want. This is a fairly common git workflow. What happens after the merges? Does one maintain the branches somehow, or do

Re: RFC: migrating to git

2011-01-12 Thread Claus Reinke
We can't even do this reliably with darcs. Several times I've tried to unpull one of Simon's patches to work around a bug, and the dependencies end up being more than just the textual dependencies. Then I have to fall back to unpulling by date, which is what git would do. And then sometimes

Re: RFC: migrating to git

2011-01-12 Thread Florian Weimer
* Simon Marlow: > Thanks for this. I distilled your example into a shell script that > uses git, and demonstrates that git gets the merge wrong: > > http://hpaste.org/42953/git_mismerge > > Still, git could get this merge right, it just doesn't (I know there > are more complex cases that would

Re: RFC: migrating to git

2011-01-12 Thread Roman Leshchinskiy
On 12/01/2011, at 09:22, Simon Marlow wrote: > On 11/01/2011 23:11, Roman Leshchinskiy wrote: >> >> A quick look at the docs seems to indicate that we'd need to do >> >> git pull >> git submodule update >> >> which doesn't look like a win over darcs-all. Also, I completely fail to >> understan

Re: RFC: migrating to git

2011-01-12 Thread Claus Reinke
The main advantages to darcs are that it can manipulate the sequence of patches better than git. The main advantage of git is that every version is accurately named. If two people have a commit with a given hash, they will have exactly the same files and history. I've been wondering about this

Re: RFC: migrating to git

2011-01-12 Thread Simon Marlow
On 11/01/2011 19:07, Roman Leshchinskiy wrote: On 11/01/2011, at 16:14, Tony Finch wrote: On Mon, 10 Jan 2011, Roman Leshchinskiy wrote: It also seems to make finding buggy patches rather hard. Have a look at `git bisect`. I'm aware of git bisect. It doesn't do what I want. I usually have

Re: RFC: migrating to git

2011-01-12 Thread Simon Marlow
On 11/01/2011 23:11, Roman Leshchinskiy wrote: On 11/01/2011, at 22:20, Simon Marlow wrote: On 11/01/11 21:57, Roman Leshchinskiy wrote: IMO, darcs-all works pretty well. I don't think I ever really had problems with missing library patches. I often see problems where someone has done 'darcs

Re: RFC: migrating to git

2011-01-11 Thread Roman Leshchinskiy
On 11/01/2011, at 22:20, Simon Marlow wrote: > On 11/01/11 21:57, Roman Leshchinskiy wrote: >> IMO, darcs-all works pretty well. I don't think I ever really had >> problems with missing library patches. > > I often see problems where someone has done 'darcs pull' rather than > './darcs-all pull'

Re: RFC: migrating to git

2011-01-11 Thread Simon Marlow
On 11/01/11 21:57, Roman Leshchinskiy wrote: On 11/01/2011, at 21:41, Iavor Diatchki wrote: If GHC and the libraries on which it depends were in git (migrated, or mirrored), then we could use git sub-modules to track the dependencies between changes to GHC and changes to the libraries. Roughly

Re: RFC: migrating to git

2011-01-11 Thread Roman Leshchinskiy
On 11/01/2011, at 21:41, Iavor Diatchki wrote: > If GHC and the libraries on which it depends were in git (migrated, or > mirrored), then we could use git sub-modules to track the dependencies > between changes to GHC and changes to the libraries. > > Roughly, the workflow would be like th

Re: RFC: migrating to git

2011-01-11 Thread Thomas Schilling
On 11 January 2011 19:07, Roman Leshchinskiy wrote: > On 11/01/2011, at 16:14, Tony Finch wrote: > >> On Mon, 10 Jan 2011, Roman Leshchinskiy wrote: >>> >>> It also seems to make finding buggy patches rather hard. >> >> Have a look at `git bisect`. > > I'm aware of git bisect. It doesn't do what I

Re: RFC: migrating to git

2011-01-11 Thread Roman Leshchinskiy
On 11/01/2011, at 16:14, Tony Finch wrote: > On Mon, 10 Jan 2011, Roman Leshchinskiy wrote: >> >> It also seems to make finding buggy patches rather hard. > > Have a look at `git bisect`. I'm aware of git bisect. It doesn't do what I want. I usually have a pretty good idea of which patch(es) m

Re: RFC: migrating to git

2011-01-11 Thread Gábor Lehel
On Mon, Jan 10, 2011 at 12:19 PM, Simon Marlow wrote: > It's time to consider again whether we should migrate GHC development from > darcs to (probably) git. > > From our perspective at GHC HQ, the biggest problem that we would hope to > solve by switching is that darcs makes branching and merging

Re: RFC: migrating to git

2011-01-11 Thread Simon Marlow
On 11/01/2011 00:36, rocon...@theorem.ca wrote: On Mon, 10 Jan 2011, Simon Marlow wrote: It's time to consider again whether we should migrate GHC development from darcs to (probably) git. From our perspective at GHC HQ, the biggest problem that we would hope to solve by switching is that darc

Re: RFC: migrating to git

2011-01-10 Thread Manuel M T Chakravarty
I agree with Roman's position. I would prefer to stay with darcs (it has its advantages and disadvantages, but has definitely been improving much in the past). In any case, all of GHC including all dependencies must be available and patchable with a *single* VCS. Mixing VCS' will lead to madn

Re: RFC: migrating to git

2011-01-10 Thread David Terei
On 10 January 2011 22:19, Simon Marlow wrote: > We're intrested in opinions from both active and potential GHC > developers/contributors.  Let us know what you think - would this make life > harder or easier for you?  Would it make you less likely or more likely to > contribute? I would really li

Re: RFC: migrating to git

2011-01-10 Thread David Peixotto
On Jan 10, 2011, at 5:19 AM, Simon Marlow wrote: > > We're intrested in opinions from both active and potential GHC > developers/contributors. Let us know what you think - would this make life > harder or easier for you? Would it make you less likely or more likely to > contribute? +1 for mo

Re: RFC: migrating to git

2011-01-10 Thread Thomas Schilling
I just want to point out that since the last discussion we collected some migration advice at http://hackage.haskell.org/trac/ghc/wiki/GitForDarcsUsers Some of it may be untested (or wrong), but it should be a good starting point. On 10 January 2011 22:15, Neil Mitchell wrote: >> As another non-

Re: RFC: migrating to git

2011-01-10 Thread Neil Mitchell
> As another non-GHC contributor, my opinion should probably also count for > little, but my experience with git has been poor. > > I have used git daily in my job for the last year.  Like Simon PJ, I > struggle to understand the underlying model of git, despite reading quite a > few tutorials.  I

Re: Mercurial? Re: RFC: migrating to git

2011-01-10 Thread Bryan O'Sullivan
On Mon, Jan 10, 2011 at 5:34 AM, Pavel Perikov wrote: > Please please consider Mercurial if migration from darcs is inevitable :) > For what it's worth, Mercurial generally interoperates quite well with git and github, using the hg-git plugin. As a longtime Mercurial user and an occasional GHC c

Re: RFC: migrating to git

2011-01-10 Thread Roman Leshchinskiy
On 10/01/2011, at 13:27, Simon Marlow wrote: > On 10/01/2011 13:02, Max Bolingbroke wrote: >> However, I remember the last time this came up there were some issues >> that might make migration painful. From the top of my head: >> >> 1) Some people expressed concern that they would have to use two

Re: RFC: migrating to git

2011-01-10 Thread Malcolm Wallace
On 10 Jan 2011, at 14:02, Gregory Collins wrote: +1. I don't have a lot of skin in this particular game (I'm not currently a GHC contributor and am unlikely to become one in the near future), but I can offer some anecdotal evidence: As another non-GHC contributor, my opinion should probably als

Re: Mercurial? Re: RFC: migrating to git

2011-01-10 Thread Johan Tibell
On Mon, Jan 10, 2011 at 5:08 PM, Pavel Perikov wrote: > Probably most valuable are the opinions of GHC development team of course :) > Git really seem to be more popular, Mercurial just seem more streamlined to > me :) Their preference if of course very important, but they partly wanted to make

Re: RFC: migrating to git

2011-01-10 Thread Thomas Schilling
I'd be for a move, but haven't contributed much lately. I use Git for all my personal projects, so I consider Git to be useful. I personally find sending patches via Git to be harder than with Darcs, but if we use Github the pull-request-based model should work well. I used Git on Windows two ye

Re: Mercurial? Re: RFC: migrating to git

2011-01-10 Thread Johan Tibell
On Mon, Jan 10, 2011 at 2:43 PM, Pavel Perikov wrote: > > On 10.01.2011, at 16:40, Johan Tibell wrote: >> While Mercurial is a fine choice, I think there are more Haskellers >> that use Git than Mercurial. Probably because GitHub is such an >> awesome service. > > Interesting. It will be great to

Re: RFC: migrating to git

2011-01-10 Thread Daniel Peebles
I fully support this (especially if it lived on github), but we should probably sort the top contributors to GHC in the past year or so and consider their opinions on the matter in that order :) I certainly would not be on that list. A git(hub)-based workflow would however facilitate any minor cont

Re: RFC: migrating to git

2011-01-10 Thread Gregory Collins
On Mon, Jan 10, 2011 at 2:38 PM, Johan Tibell wrote: >> Ultimately I'm quite concerned with keeping GHC HQ happy (as you guys >> do the lions share of the work!). I feel we should only make the >> switch if the most frequent committers (i.e. Simon, Simon and Ian) are >> *totally happy* with it and

Re: RFC: migrating to git

2011-01-10 Thread Lars Viklund
On Mon, Jan 10, 2011 at 01:27:17PM +, Simon Marlow wrote: > On 10/01/2011 13:02, Max Bolingbroke wrote: >> 2) There was also concern that Git isn't so great on Windows. I have >> heard that this is less of an issue now, but I never personally >> suffered from any problems, so can't be sure. (FW

Re: Mercurial? Re: RFC: migrating to git

2011-01-10 Thread Johan Tibell
On Mon, Jan 10, 2011 at 2:34 PM, Pavel Perikov wrote: > Please please consider Mercurial if migration from darcs is inevitable :) While Mercurial is a fine choice, I think there are more Haskellers that use Git than Mercurial. Probably because GitHub is such an awesome service. Johan __

Re: RFC: migrating to git

2011-01-10 Thread Johan Tibell
On Mon, Jan 10, 2011 at 2:02 PM, Max Bolingbroke wrote: > Naturally other workflows are possible and I'm sure other list members > will chime in with their own favourites :-) Here's the flow I use: http://nvie.com/posts/a-successful-git-branching-model/ with the exception of having the master b

Re: RFC: migrating to git

2011-01-10 Thread Johan Tibell
On Mon, Jan 10, 2011 at 12:19 PM, Simon Marlow wrote: > We're intrested in opinions from both active and potential GHC > developers/contributors.  Let us know what you think - would this make life > harder or easier for you?  Would it make you less likely or more likely to > contribute? I would a

Re: RFC: migrating to git

2011-01-10 Thread Simon Marlow
On 10/01/2011 13:02, Max Bolingbroke wrote: On 10 January 2011 11:19, Simon Marlow wrote: Let us know what you think - would this make life harder or easier for you? Would it make you less likely or more likely to contribute? Well, as a sometime-contributor I would certainly be happier hacki

Re: RFC: migrating to git

2011-01-10 Thread Max Bolingbroke
On 10 January 2011 11:19, Simon Marlow wrote: > Let us know what you think - would this make life > harder or easier for you?  Would it make you less likely or more likely to > contribute? Well, as a sometime-contributor I would certainly be happier hacking on GHC if it were git based. When worki

RFC: migrating to git

2011-01-10 Thread Simon Marlow
It's time to consider again whether we should migrate GHC development from darcs to (probably) git. From our perspective at GHC HQ, the biggest problem that we would hope to solve by switching is that darcs makes branching and merging very difficult for us. We have a few branches of HEAD that