WIP: Bump resolver used in release.hs

[snoyberg]

Note: Documentation fixes for https://docs.haskellstack.org/en/stable/ should target the "stable" branch, not master.

Please include the following checklist in your PR:

• Any changes that could be relevant to users have been recorded in the ChangeLog.md
• The documentation has been updated, if necessary.

Please also shortly describe how you tested your change. Bonus points for added tests!

[borsboom]

I think the integration tests might be failing due to using an LTS that requires a different GHC version than is already available. Probably best to bump the integration tests to also use a consistent LTS.

One of these days I might just drop the release.hs script entirely and replace it with a simple shell script, since CI is now handling all the builds and there's no longer the need for so much complexity. Probably not worth doing unless significant changes would be needed though.

[snoyberg]

One of these days I might just drop the release.hs script entirely and replace it with a simple shell script,

+1 from me on that happening ultimately, but agreed, no rush

[snoyberg]

I'm in particular unable to fix up the Nix problems here. If someone else is interested in taking a crack at that, I'd really appreciate it.

[qrilka]

@snoyberg I've tried it out locally but couldn't reproduce, the error

error: attribute 'ghc8104' missing, at (string):1:43
5259
(use '--show-trace' to show detailed location information)

means that there is no ghc8.10.4 in nixpkgs but it seems to be present in the latest <nixpkgs> that I just pulled - https://github.com/NixOS/nixpkgs/blob/84aa23742f6c72501f9cc209f29c438766f5352d/pkgs/top-level/haskell-packages.nix#L68

[snoyberg]

I discovered the line in question here:

stack/.github/workflows/integration-tests.yml

Line 58 in d1eef3f

nix-channel --add https://nixos.org/channels/nixos-19.09 nixpkgs

We locked it down previously to make the test suite reproducible. But I have no idea what we should bump it to instead.

[qrilka]

Oh, I completely forgot that it was pinned, sorry, will take a look

[snoyberg]

FYI, I'm already including a workaround in this PR:

95d214c

It's not as good, since it still requires two GHCs to be installed, but it does work around using the older GHC for release.hs itself.

[qrilka]

@snoyberg it looks like we can't use the last stable version 20.09 as there's no 8.10.4 there:

$ NIX_PATH='nixpkgs=https://github.com/NixOS/nixpkgs/archive/20.09.tar.gz'  nix-instantiate --eval -E 'builtins.attrNames((import <nixpkgs> {}).haskell.compiler)'
unpacking 'https://github.com/NixOS/nixpkgs/archive/20.09.tar.gz'...
[ "ghc8101" "ghc8102" "ghc822Binary" "ghc865" "ghc865Binary" "ghc882" "ghc883" "ghc884" "ghcHEAD" "ghcjs" "ghcjs86" "integer-simple" "native-bignum" ]

but 21.05 is almost released so I guess this should be good enough as an option

$ NIX_PATH='nixpkgs=https://github.com/NixOS/nixpkgs/archive/release-21.05.tar.gz'  nix-instantiate --eval -E 'builtins.attrNames((import <nixpkgs> {}).haskell.compiler)'
unpacking 'https://github.com/NixOS/nixpkgs/archive/release-21.05.tar.gz'...
[ "ghc8102Binary" "ghc8102BinaryMinimal" "ghc8104" "ghc865Binary" "ghc884" "ghc901" "ghcHEAD" "integer-simple" "native-bignum" ]

but there's no channel for it yet so some other way of pinning is needed

[qrilka]

@snoyberg I guess using env vars in that test could be even more explicit and we'll have the same config both in CI and locally and it looks like NIX_PATH is the way to go:

NIX_PATH='nixpkgs=https://github.com/NixOS/nixpkgs/archive/20.09.tar.gz' stack exec -- nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
"20.09pre-git"

With the URL to set in the test https://github.com/NixOS/nixpkgs/archive/release-21.05.tar.gz

[mpilgrem]

Rather late in the day, I realised that this pull request was seeking to do part of what I am trying to do in pull request #5697 (move stack to lts-19.7/GHC 9.0.2) - but this request is for lts-8.10.4/lts-17.10. My GHC 9.0.2 pull request passes the unit tests, and the integration tests on Windows, but I am stuck with [1] the integration tests running on macos-latest (my current task) and [2] the integration tests that need 'alpine' or 'docker' (see #5736 (comment)). I have not worked out how I can test CI in my fork, so I am trying to fix the CI in my pull request.

[mpilgrem]

I am going to close this pull request, as I think it has been overtaken by either #5697 (which was trying to move Stack to the current LTS, being GHC 9.0.2) or, more likely, #5763 (which is trying to move Stack to GHC 9.2.3 - the subject of the current nightly resolver).