Version control systems

[Duncan Coutts]

On Mon, 2008-08-11 at 12:21 +0200, Thomas Schilling wrote:

> However, I think that it would be really disappointing if we would  
> not move to Git for the main GHC repository.  Simon M reported that a  
> merge took him over a whole day, Norman reported two weeks of lost  
> work, Don reported corrupted repos, Simon PJ reported that in order  
> to avoid conflicts he constantly unrecords and re-records one big  
> patch;  all that doesn't give much confidence in Darcs.

We all accept there are problems with darcs v1 and the darcs v1 repo
format for larger projects that do lots of development in branches and
then merge back.

> Additionally, no-one except David seems to actually understand Darcs'  
> theory (and we don't even know if David actually does.)  Darcs 2  
> claims to fix those problems, but I don't know how many are actually  
> using it. 

It's not clear to me that we've really bothered to find out. The last
evaluation in relation to ghc that I'm aware of was prior to the 2.0
release. My impression is that we've all complained about the darcs v1
problems (justly) but spent the most effort investigating things other
than darcs v2 which would be the easiest to upgrade to and not have the
problems of using two different systems for ghc vs other libs.

On a slightly related issue, we're currently evaluating upgrading to
darcs 2 for code.h.o. We'll let people know how that goes. It's not
directly relevant to ghc since we'd not be switching to darcs v2 format
(that's the prerogative of the repo owners, not code.h.o admins).

Duncan