[Nix-dev] Stackage Support Will Be Discontinued

[Peter Simons]

Hi Anthony,

 > I know you didn't ask for feedback [...].

I'm always happy to get feedback!

 > If the top priority is receiving bug fixes, then keeping an LTS-4,
 > LTS-5, LTS-6, etc. that tracks the most recent minor version makes
 > sense.

You seem to be saying that keeping an old major release like LTS-4
around would somehow help us receive more bug fixes, but I can't see how
that would be true. According to git://github.com/fpco/lts-haskell.git,
the last time any LTS-4 update occurred was on 2016-01-18 -- almost half
a year ago. Surely, there have been point updates that fix bugs between
then and now, but LTS-4 does not seem to receive them, no? That is
because no-one maintains LTS-4. Stackage has moved on to LTS-5, or
rather: LTS-6 by now.

So how exactly do we receive more bug fixes by distributing LTS-4?


 > You say, "Stackage does not "maintain" any of its LTS releases," but
 > the minor releases are precisely the offered maintenance.

The thing is just that minor releases occur only for the latest major
release. LTS-6 has minor release at the moment, but LTS-5, LTS-4, etc.
do not! I agree that it would make sense to continue to distribute LTS-4
if there were further minor releases to come out for that package set.
But there won't be any. As far as Stackage is concerned, LTS-4 is dead.


 > Furthermore, there is no reason a new LTS-5 release can not be issued
 > after the first release of LTS-6.

Sure, this *could* happen and it would be great! Then we'd have a real
long-term supported package set that would be worth-while to distribute.


 > The cultural prominence of Stackage means that the need for security
 > fixes to older versions can actually be promulgated because Stackage
 > has users.

I am sorry, but I have no idea what that sentence means.


 > For a modest application, specifying a particular Stackage release is
 > a concise way of freezing Haskell dependencies.

In Nix, we can solve these things by tagging a specific version of
Nixpkgs and sticking to that. Not only will that freeze the Haskell
dependencies, but it will also freeze all other dependencies, too.


 > A typical Stackage definition is about 70KB.

Huh? That's not what I am seeing in git://github.com/fpco/lts-haskell.git:

   $ ls -lh lts-6.2.yaml
   -rw-r--r-- 1 simons users 4.7M Jun  6 11:58 lts-6.2.yaml


 > Nix definitions require nearly 10x that space is unfortunate, but I
 > had expected a Nix solution to this issue rather than giving up on
 > versions altogether.

Oh, come on. I wrote a very long and detailed explanation of *why* we
give up on tracking Hackage, and to boil that whole article down to "it
was using too much disk space" is just silly.

Best regards,
Peter