stack build error: attribute ‘ghc822’ missing, at (string):1:53

Question

I am attempting to build my haskell project on NixOS.

Running $ stack build gives the following error.

$ stack build
error: attribute ‘ghc82         


        

Answer 1

You can provide an old GHC version using a shell.nix file place in the root of your project:

with import (fetchTarball https://github.com/NixOS/nixpkgs/archive/83b35508c6491103cd16a796758e07417a28698b.tar.gz) {};
let ghc = haskell.compiler.ghc802;
in haskell.lib.buildStackProject {
    inherit ghc;
    name = "myEnv";
    buildInputs = [ pcre ];
}

Use a tar url from https://github.com/NixOS/nixpkgs/releases for a version of nixpkgs that contains the GHC version you need.

Then run nix-shell in the root of the project. This will put you into a shell in which you can perform stack build successfully since it would have access to the correct GHC version.