haskell-cabal2nix template not working out of the box

[MaxDaten]

$ nix --version
nix (Nix) 2.4pre20210601_5985b8b

---

Hi,

I'm currently diving into nix flakes, thanks for your blog post about flakes. I'm following this guide to generate a cabal2nix hakyll site-generator project: https://serokell.io/blog/practical-nix-flakes#packaging-existing-applications

executing (in a subfolder of my repo):

nix flake init -t github:serokell/templates#haskell-cabal2nix

places excatly this repo's haskell-cabal2nix/flake.nix in my project. I replaced packageName with:

- packageName = throw "put your package name here!";
+ packageName = "site-generator";

executing:

nix build

results in error:

error: builder for '/nix/store/pi1vw77kall69hjql189qdw13hf6zvh7-cabal2nix-site-generator.drv' failed with exit code 1;
       last 2 log lines:
       > installing
       > cabal2nix: nix-prefetch-url: createProcess: runInteractiveProcess: exec: does not exist (No such file or directory)
       For full logs, run 'nix log /nix/store/pi1vw77kall69hjql189qdw13hf6zvh7-cabal2nix-site-generator.drv'.
(use '--show-trace' to show detailed location information)

changing:

 packages.${packageName} =
-  haskellPackages.callCabal2nix packageName self rec {
+  haskellPackages.callCabal2nix packageName ./. rec {
    # Dependency overrides go here
  };

renders nix build successful.

Am I missing something or is it because of a recent change in nix?

Greetings

Jan

[balsoft]

This is a really interesting issue, I'll look into it. Thanks for noticing!