[darcs-users] old-fashioned repository support in darcs 2.8

[Guillaume Hoffmann]

> The question is if it's practical to aim for it in 2.8.

We are almost as far as possible from the next release, this is now
that this kind of changes should happen, so we have time to
consolidate them for the release.

> If we don't reach any sort of consensus, I offer to commit to removing
> OF support by Darcs 2.8 if you are willing to do the job of adequately
> preparing users for what's ahead. I think this means getting the
> communications under control (darcs users may not read darcs-users or
> any darcs mediums) and also  making sure that Darcs 2.5.1 does the right
> things.

Let us see what we have and what we can do before 2.8.

Since darcs 2.4, users see a warning message when getting from an OF
repository. It does not really say that OF is deprecated, but
recommends upgrading, which is not far.

I guess (but can't prove) that non-power users of darcs >= 2 do not
create OF repositories when using the commands get, put or init. Why
would they? It's not in any tutorial, the help discourages the use of
--old flags ("Minimal features. What older repos use".), except when
the repo needs to be read/written by darcs-1 binaries.

We can release a version 2.5.1 that includes the "More visible
old-fashioned to hashed notice" patch that is currently in the
screened branch.

We can directly contact by mail the people who keep OF repos available
online to announce our 2.8 roadmap.

Moreover, it be useful to blog about this as soon as possible in order
to spread the word (reddit programming and haskell), and present it as
part of the evolution of darcs towards being a more interesting and
up-to-date system. This is similar to what you are writing in
http://wiki.darcs.net/Mission .

Finally, the release announcement of 2.8 will also talk about that, so
users can decide whether to upgrade.

>> Lastly, I do not think we should commit to the contract "if, by 2.8,
>> hashed repos are not as fast as OF repos we should put back full OF
>> support in the code".
>
> I don't think anybody was suggesting that :-)

Oops, what I read was more "we commit to bring back hashed performance
on par with OF", so I unconsciously made up the "or else" part. Sorry
for the wrong interpretation and miscommunication.



So, can we decide about that? The steps should be:

1) we decide to drop OF writing support in 2.8 (and probably
borderline commands like whatsnew, diff), which basically leaves get
and pull.
2) we update http://wiki.darcs.net/Roadmap so that people see it's
part of a whole set of changes that will make 2.8 über cool.
3) we prepare a mail to be sent privately to owners of public OF
repositories (typically, in the haskell community) to explain what
comes in darcs 2.8 and later (citing the roadmap page)
4) prepare a blog post about the 2.8 roadmap, explaining the whys of
OF support change, and telling a release 2.5.1 is prepared.
5) bring on the patches for 1)! May it be from Petr's adventure patch
bundle, or any other source, again this is to be discussed. Someone
(maybe you, Eric, since you propose) should have a hat of "OF removal
supervisor", whose mission ends when the patches are all accepted into
HEAD.

I can take care of parts 3) and 4) (after we discuss the contents of
the messages on the list).

Guillaume