[darcs-users] upgrade from darcs-1 to darcs-2

[Henning Thielemann]

On Wed, 4 Mar 2015, Simon Michael wrote:

> On this: it's great that Ganesh is willing to code it up, but I find it 
> hard to be enthusiastic. hub.darcs.net is a service I offer for free, 
> dev/ops time is always scarce and I doubt that perpetuating the oldest 
> data formats is the best use of my & our energy. IMHO this will just 
> increase the surface area for bugs and weird operational issues that 
> will need to be dealt with, for ever.

As far as I understand darcs will continue to support darcs-1 hashed 
format anyway. I do not know how complicated support for hashed format in 
darcsden is. I even wouldn't be sad, if support for hashed format is 
restricted, e.g. it's ok for me if inspecting changes via 
http://hub.darcs.net does not work for hashed format. But maybe the 
complication is just caused by supporting more than one format. And maybe 
this complication comes anyway, if a darcs-3 format is introduced in a 
shiny future?


> In fact I've always thought that part of hub.darcs.net's value would be 
> to once and for all, FINALLY provide a good reason for the last 
> hold-outs to upgrade their repos away from the 
> exponential-bug-vulnerable old-fashioned format which has besmirched 
> darcs' reputation for so long.

My last state of knowledge is that the exponential merge time bug is not 
gone with darcs-2, it only occurs in different situations, right? Thus I 
deferred updating my repositories so far. If the exponential merge problem 
is finally resolved I would reconsider converting my repos. If new change 
types like indentation changes and block-moves are added I would even 
reconsider more quickly (although new features are error-prone and in a 
repository this is critical).


> Can you describe your situation in more detail ? Are these repos haskell 
> ecosystem-related, public, private... ? The usual course for this 
> upgrade is to upgrade the master repo and then have all contributors 
> re-fetch their clones one time. Can't you do that ?

I don't know how many people follow my repositories. But I have many 
branches of the same repositories on my machine, e.g. one clean branch for 
hackage upload and other branches with experimental code. The repositories 
in the old format are of course older than the ones I have already 
uploaded to hub.darcs.net. They include projects like numeric-prelude, 
sox, synthesizer, midi, alsa, jack, fft, gnuplot, data-accessor, 
storablevector, llvm-tf, propability, utility-ht. A quick count on 
code.haskell.org results in about 80 such repositories.