[Nix-dev] Stackage Support Will Be Discontinued

[Peter Simons]

Hi Anthony,

 > I draw a distinction between newer minor versions obsoleting old ones
 > for purposes of bug fixes vs. for purposes of freezing packages.

I am sorry, but I don't understand that distinction. In your original
response you suggested that dropping old LTS major releases like LTS-4
from Nixpkgs would reduce your ability to use Nix, i.e. it would make
Nixpkgs less useful to you than it is today. I have a hard time seeing
how what might be the case, so I wonder whether you'd mind explaining to
me a concrete use case that works for you today but that won't work
after LTS-4 has been dropped?


 > The Stackage design is such that they *can* release bug fixes for
 > older versions to help their users.

Yes, I totally agree. Once Stackage starts releasing updates for older
LTS versions, it's a completely different situation and then carrying
around older LTS major releases would actually make sense.


 > You are removing that opportunity because it hasn't been used yet.

I don't intend to remove any "opportunities" here. All I want to remove
is some 850,000 lines of untested, unmaintained code from the Nixpkgs
repository. If there is a compelling use case for that code, then let's
talk about it! At the moment, however, the cost / benefit ratio of
keeping all those package sets around strikes me as bad, really, and I
don't think we should keep distributing that code unless there's a real
benefit to the effort.


 > As companies adopt Stackage package sets, they will have applications
 > in production that they, A) really want bug fixes for; and B) do not
 > want to keep on the hackage treadmill by following new releases. If a
 > bug is found in an LTS-5 package within the next few months, a stink
 > will be raised.

I think everyone agrees that we *want* LTS-5 updates to come out even
after the release of LTS-6. Whether that is actually going to happen or
not, however, is speculation and neither you nor me can possibly know.


 >> In Nix, we [freeze dependencies] 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.
 >
 > This is a big step backwards. You object that Stackage has not yet
 > used their existing mechanism for releasing bug fixes for older
 > Haskell libraries, and respond by promoting a mechanism that admits
 > no bug fixes for any software at all.

I have no idea what you are talking about. Nix offers a myriad of
different ways to cherry pick updates into a stable version of the
package set.

Best regards,
Peter