Unfriendly HEAD is unfriendly

[Simon Marlow]

Claus Reinke wrote:
> going back from the use of darcs-specific 'pull --intersection' (but 
> still relying on selective pull in some form), and addressing Roman's 
> point about avoiding conflicts:
> 
> 0. for each platform, have a list of successfully tested patches
> 1. humans (GHC users, needing a working build of HEAD):
>        pull the lists of tested patches
>        pull only the patches on the list for their platform
>            (this could be handled by a script like darcs-all, provided
>             that the VCS supports selective pulling)
> 2. humans (GHC developers, needing a validated HEAD):
>        pull all patches into a local reference repo
>        pull tested-only patches into a local validate repo
>        develop/validate in validate repo
>        check for conflicts wrt reference repo
>        push validated and conflict-free patches to main_repo
>        watch out for breakage reports from builders on other platforms
> 3. builders (on platform X, with list of successfully tested patches)
>        pull all patches
>        try to build
>            if successfull, add all new patches to platform X list 
>            if fails, publish list of all new patches as failing
>                (in need of attention for platform X)
> 
> Also, isn't one of the reasons for switching VCS to make
> conflicts less of an issue?

selective pull only really works in darcs.  In the other VCSs it implies 
having a separate branch for each re-ordering of the patches, and hoping 
that merge works properly.

Cheers,
	Simon