[Haskell-cafe] ANN: HDBC v2.0 now available

[Duncan Coutts]

On Sun, 2009-02-01 at 15:56 +0100, Niklas Broberg wrote:
> > So in the next cabal-install release (which should be pretty soon now)
> > configure will do the same thing and pick base 3 unless you specify
> > build-depends base >= 4.
> 
> ... and so there will never be any incentive for these many packages
> to migrate to base-4, which also has consequences for packages that do
> want to use base-4, but also want to depend on such packages. And so
> base-3 will live on in eternity, and there was never any point in
> doing that new base release at all.

> I really really think this is the wrong way to go. Occasional
> destruction is desperately needed for progress, else things will
> invariably stagnate.

I disagree. Having everything fail (we measured it as ~90% of hackage)
when people upgraded to ghc-6.10 would have been a disaster. Do you
recall the screaming, wailing and gnashing of teeth after the release of
ghc-6.8 when most of hackage broke? We (I mean ghc and cabal hackers)
got a lot of flak for not making the upgrade process easier and
needlessly breaking everyone's  perfectly good packages.

This time round we went to a lot of effort to make the upgrade process
smooth. And for the most part it was. Only a small proportion of hackage
packages broke.

Now I agree that there is a problem with new packages where the
configure selects base 4 but install selects base 3. I've improved that
in the darcs version.

You're also right that during the lifespan of base 4 we need to
encourage new releases to start working with it because we cannot stick
with base 3 for ever. Doing that with warnings hints etc is the way to
go. Destruction is not such a friendly approach. We do not need to make
the users suffer, we just need to inform and persuade developers
uploading new releases to do the right thing.

Duncan