Custom stack resolver in stack.yaml fails

[codygman]

I can work around this by inlining the contents of that resolver in changing packages to extra-deps So I know I have everything else working. Sadly my team needs that for other stuff and doesn't see the work around of removing the resolver and using a plain stack.yaml as an option.

# stack.yaml
resolver: https://raw.githubusercontent.com/EdutainmentLIVE/snapshot/f5f60d88a128aff3da0e5fd508a3e2aacd2ca109/snapshot.yaml

Results in:

host name: Just "raw.githubusercontent.com", service name: Just "443"): does not exist (Name or service not known))

Full log:

smurf  July-haskell-nix 「↪ 𝚫 ✔ 📁 」 on  (us-east-1) took 25s 
✖1 ❯ nix build
warning: Git tree '/home/cody/smurf' is dirty
trace: To make project.stack-nix for haskell-project a fixed-output derivation but not materialized, set `stack-sha256` to the output of the 'calculateMaterializedSha' script in 'passthru'.
trace: To materialize project.stack-nix for haskell-project entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
trace: WARNING: `cleanSourceWith` called on /nix/store/qy510ayhgci7wksf6qzkbac6cszcg8mp-source without a `name`. Consider adding `name = "qy510ayhgci7wksf6qzkbac6cszcg8mp-source";`
error: builder for '/nix/store/pd7zjfwh977mkyd3zrjwqmdk1cnq9i9v-stack-repos.drv' failed with exit code 1;
       last 10 log lines:
       >   queryString          = ""
       >   method               = "GET"
       >   proxy                = Nothing
       >   rawBody              = False
       >   redirectCount        = 10
       >   responseTimeout      = ResponseTimeoutDefault
       >   requestVersion       = HTTP/1.1
       >   proxySecureMode      = ProxySecureWithConnect
       > }
       >  (ConnectionFailure Network.Socket.getAddrInfo (called with preferred socket type/protocol: AddrInfo {addrFlags = [AI_ADDRCONFIG], addrFamily = AF_UNSPEC, addrSocketType = Stream, addrProtocol = 0, addrAddress = 0.0.0.0:0, addrCanonName = Nothing}, host name: Just "raw.githubusercontent.com", service name: Just "443"): does not exist (Name or service not known))
       For full logs, run 'nix log /nix/store/pd7zjfwh977mkyd3zrjwqmdk1cnq9i9v-stack-repos.drv'.
(use '--show-trace' to show detailed location information)

[codygman]

I found out in libera.chat#haskell.nix that this is not a bug but something that nix intentionally doesn't allow.

[codygman]

It appears there is an option thanks to @balsoft I came up with this but still have an issue:

{
  description = "A very basic flake";
  inputs.haskellNix.url = "github:input-output-hk/haskell.nix";
  inputs.nixpkgs.follows = "haskellNix/nixpkgs-unstable";
  inputs.flake-utils.url = "github:numtide/flake-utils";
  outputs = { self, nixpkgs, flake-utils, haskellNix }:
    flake-utils.lib.eachSystem [ "x86_64-linux" "x86_64-darwin" ] (system:
    let
      overlays = [ haskellNix.overlay
        (final: prev: {
          # This overlay adds our project to pkgs
          myproj =
            final.haskell-nix.project' {
              src = ./.;
              resolverSha256 = "0zhmk6qasy3zfr616n7a1kj34m16dcv47gjfvb2424wk7d9w1xr1";
              compiler-nix-name = "ghc8104";
              # This is used by `nix develop .` to open a shell for use with
              # `cabal`, `hlint` and `haskell-language-server`
              shell.tools = {
                cabal = {};
                hlint = {};
                haskell-language-server = {};
              };
              branchMap = {
                "https://github.com/brendanhay/amazonka"."020bc7bde47bb235e448c76088dc44d6cec13e9b" = "develop";
              };
              # This adds `js-unknown-ghcjs-cabal` to the shell.
              # shell.crossPlatform = p: [p.ghcjs];
            };
        })
      ];
      pkgs = import nixpkgs { inherit system overlays; };
      flake = pkgs.myproj.flake {
        # This adds support for `nix build .#js-unknown-ghcjs-cabal:myproj:exe:myproj`
        # crossPlatforms = p: [p.ghcjs];
      };
    in flake // {
      # Built by `nix build .`
      defaultPackage = flake.packages."myproj:exe:myproj";
    });
}

Output:

✖1 ❯ nix build
warning: Git tree '/home/cody/myproj' is dirty
trace: To make project.stack-nix for haskell-project a fixed-output derivation but not materialized, set `stack-sha256` to the output of the 'calculateMaterializedSha' script in 'passthru'.
trace: To materialize project.stack-nix for haskell-project entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
trace: WARNING: `cleanSourceWith` called on /nix/store/sk8d3r8brx6frzrqd7rxfnk38rmq29vh-source without a `name`. Consider adding `name = "sk8d3r8brx6frzrqd7rxfnk38rmq29vh-source";`
error: builder for '/nix/store/c8yhryj23nnfq7azzk4py3iknw7w09vj-stack-repos.drv' failed with exit code 1;
       last 4 log lines:
       > substituteStream(): WARNING: pattern '# nix-sha256:' doesn't match anything in file 'stack.yaml'
       > stack-repos: AesonException "Error in $: key \"name\" not found"
       > CallStack (from HasCallStack):
       >   error, called at lib/Stack2nix/External/Resolve.hs:45:25 in nix-tools-0.1.0.0-HSKLHXvL6X11Z9A8iBqCaD:Stack2nix.External.Resolve
       For full logs, run 'nix log /nix/store/c8yhryj23nnfq7azzk4py3iknw7w09vj-stack-repos.drv'.
(use '--show-trace' to show detailed location information)

myproj  July-haskell-nix 「↪ 𝚫 📁 」 on  (us-east-1) took 2s 
✖1 ❯ 

[codygman]

It seems this is working, but two things made it tricky:

• You get a very unhelpful error if your resolver file does not have a name: field
• I forgot to update the resolver hash after adding a name to my github branch and it silently used the old version

After addressing both of those though things work!

[locallycompact]

When I try your exact example I get:

trace: To make project.stack-nix for haskell-project a fixed-output derivation but not materialized, set `stack-sha256` to the output of the 'calculateMaterializedSha' script in 'passthru'.
trace: To materialize project.stack-nix for haskell-project entirely, pass a writable path as the `materialized` argument and run the 'updateMaterialized' script in 'passthru'.
error: fetchurl requires either `url` or `urls` to be set
(use '--show-trace' to show detailed location information)

[locallycompact]

Here's a reproduction using your flake.nix expression and a stack manifest with your resolver in resulting in error: fetchurl requires either urlorurls to be set

https://github.com/locallycompact/custom-stack-resolver-bug

[locallycompact]

Ok, the name: field needs to be in the resolver, for some reason I'd convinced myself it was going in the stack.yaml. Ignore me.

[locallycompact]

Ok, related though is this behaviour, setting:

resolver:
  url: https://gitlab.homotopic.tech/packaging/stackage-snapshots/-/raw/master/nightly/2021/8/5.yaml
  size: 605
  sha256: 4b996341941b8e0c41aecfa0d1852c22e8747e7deeee87a9f862c7257b8c47df

is a valid stack configuration, but this will fail in stack2nix with the fetchurl error above.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.