[darcs-users] RE: darcs'ing fptools

[Simon Marlow]

On 11 October 2005 15:22, John Goerzen wrote:

> On Tue, Oct 11, 2005 at 10:58:08AM +0100, Simon Marlow wrote:
> 
> [ various snipping ]
> 
>> The following projects are not in active development and could stay
>> in CVS: 
>> 
>>    greencard, green-card, haggis, hdirect, hood, hws, hx
> 
> True, it probably wouldn't matter much.  OTOH, if some parts are being
> converted at this point, I'd suggest just going ahead and converting
> the rest.  That way, you don't have to maintain/watch two different
> systems. And, should these packages see development in the future,
> they'd be ready to go.

The problem I was tryig to avoid was having to figure out how to share
the fptools build system between multiple projects in darcs.  This was
the sticking point last time, IIRC.  I suppose you could just duplicate
the shared parts in each repo, it's not a big deal.

>> What I'm not clear about is how to handle the libraries subtree. 
>> This is used by nhc98 and Hugs too, and presumably it would be
>> inconvenient for them if they had to 'darcs get' an entire GHC tree
>> just to get the libraries.  Ideas?  Perhaps we should have a
>> separate libraries repository from which we can push/pull patches
>> to/from the GHC repo? Perhaps we should convert libraries into a
>> darcs repo of its own, and then pull it into the GHC repo (how do
>> you create the repos such that this is possible - do they have to
>> have a common root of some kind?). 
> 
> It is possible to have nested darcs repos.

Ok, that sounds like a reasonable solution.

So, we'll have one darcs repo for GHC containing fptools with subdirs
distrib, docs, ghc, glafp-utils, mk.  Plus separate repos for libraries,
nofib, and testsuite.

>> Also, we'll need a two-way CVS gateway between the old fptools and
>> the GHC darcs repo (and the libraries repo), at least for the time
>> being. 
> 
> There is some information at
>
http://darcs.net/DarcsWiki/Tailor/CvSync#head-ef1c647c5b2be460867dc49aec
fb05a6bc02df1f
> about doing this, so it is possible.
> 
> I haven't specifically tried this with tailor & darcs.
> 
> However, in general, it seems that these sort of arrangements are
> somewhat flaky, require a lot of babysitting, and are prone to error.
> 
> I'd rather suggest a cutoff teim.  I don't mind doing a "practice" and
> then a "real" conversion, if that's what it would take.  The practice
> conversion would let people poke at things and make sure that they are
> working as they like.

That seems a bit extreme, I envisage lots of grumbling from existing CVS
users.  Any tailor.py experts willing to help out?

>> Long term, when we no longer need CVS, I'd like to rearrange the GHC
>> tree.  We can rename the root from fptools to ghc (yay!) and flatten
>> the hierarchy.
> 
> That might be another thing to consider doing right now.

If we're doing two-way syncing, large-scale reorganisations of the tree
are certain to cause difficulties.  I'll leave it until we are free of
CVS.

Cheers,
	Simon