Ghc-wasm time compilation error

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1

Hi guys! i’m trying to compile a cabal project using the wasm backend with flavor 9.12, but i’m hitting the following error:

building library for time-1.12.2...
ib/cbits/HsTime.c:14:5: error:
     error: call to undeclared function 'tzset'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
       14 |     tzset();
          |     ^
   |
14 |     tzset();
   |     ^

1 error generated.
`wasm32-wasi-clang' failed in phase `C Compiler'. (Exit code: 1)
Error: [Cabal-7125]

In my current cabal.project file i have the following fields:

allow-newer:
  template-haskell,
  base,
  ghc-prim,
  ghc-experimental

if arch(wasm32)
  shared: True


package aeson
  flags: -ordered-keymap

I have to use allow newer since i’m hitting conflicts on base and template-haskell when trying to compile the following packages :

base >= 4.7 && < 5

text >= 1.2

jsaddle

jsaddle-wasm

singletons

singletons-base

ghc-experimental

template-haskell

However, if instead of calling wasm32-wasi-cabal, i call normal cabal, the project compiles fine. Any idea what might be happening?

2

With a little bit of help of the great Terror jack I found out that the time version 1.12 is too old. If i add a constraint: time >= 1.14 and add time to the allow newer list it now compiles.

However, adding so many allow newer feels strange. Specially since the wasi-wasm32-cabal package list seems to include packages that are tested with the 9.10 instead of the latest versions which are tested with 9.12 (which is the flavor I’m using). Is this supposed to work like this?

I’m dropping my flake.nix for reference

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
    ghc-wasm.url = "gitlab:haskell-wasm/ghc-wasm-meta?host=gitlab.haskell.org";

  };
  outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
    flake-parts.lib.mkFlake { inherit inputs; } {
      systems = nixpkgs.lib.systems.flakeExposed;
      imports = [];

      perSystem = { self', pkgs, config, ... }: {

        devShells.default = pkgs.mkShell {
          name = "haskell-template";
          meta.description = "Haskell development environment";
          inputsFrom = [
          ];
          nativeBuildInputs =
            [ inputs.ghc-wasm.packages.${pkgs.system}.all_9_12
              pkgs.hpack
              pkgs.just
              pkgs.haskellPackages.Cabal_3_14_2_0
              pkgs.haskell.compiler.ghc912
              (pkgs.haskell-language-server.override { supportedGhcVersions = [ "912" ]; })
              pkgs.haskellPackages.hoogle
            ];
        };
      };
    };
}