In reply to @vengmark2:matrix.org
Did that work? If so, would you be OK to create a PR?

nix-build default.nix

error:
       … while evaluating the attribute 'drvPath'

         at /nix/store/pp307nbzkgsd6393zl2i9j4j86z5nz9b-nixpkgs-src/lib/customisation.nix:228:7:

          227|     in commonAttrs // {
          228|       drvPath = assert condition; drv.drvPath;
             |       ^
          229|       outPath = assert condition; drv.outPath;

       … while calling the 'derivationStrict' builtin

         at /builtin/derivation.nix:9:12: (source not available)

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: function 'anonymous lambda' called with unexpected argument 'flit-core'

       at /nix/store/pp307nbzkgsd6393zl2i9j4j86z5nz9b-nixpkgs-src/pkgs/development/python-modules/wheel/default.nix:1:1:

            1| { lib
             | ^
            2| , buildPythonPackage

I'm a bit confused by niv since I don't usually use it, I tried to run the command both inside the nix-shell including niv and outside and I'm still getting the same error

The error message when running nix build .is this one

error: flake 'path/to/project' does not provide attribute 'packages.x86_64-linux.default' or 'defaultPackage.x86_64-linux'

error:
       … while evaluating the attribute 'pkgs.buildPythonPackage'

         at /nix/store/p2hby44a0qzrnd1vxcpcgfav6160rmcv-source/pkgs/development/interpreters/python/passthrufun.nix:87:5:

           86|     withPackages = import ./with-packages.nix { inherit buildEnv pythonPackages;};
           87|     pkgs = pythonPackages;
             |     ^
           88|     interpreter = "${self}/bin/${executable}";

       … while calling the 'mapAttrs' builtin

         at /nix/store/p2hby44a0qzrnd1vxcpcgfav6160rmcv-source/pkgs/development/interpreters/python/passthrufun.nix:31:8:

           30|           value;
           31|     in lib.mapAttrs func items;
             |        ^
           32|   in ensurePythonModules (callPackage

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: value is a function while a set was expected

In reply to @ericadelagnier:multi.coop
When using flakes, I was able to run my flake (yeah !) but I now have a question regarding the dependency environment to run my app with gunicorn since I can't seems to find the right syntax to build it (the README give an default.nix as example and I'm don't know enough about flakes to reproduce it)

I think this will work with nix build .

flake.nix:

{
  description = "Python application packaged using poetry2nix";

  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
  inputs.poetry2nix.url = "github:nix-community/poetry2nix";
  inputs.flake-utils.url = "github:numtide/flake-utils";

  outputs =
    {
      self,
      nixpkgs,
      poetry2nix,
      flake-utils,
    }:
    flake-utils.lib.eachDefaultSystem (
      system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
        # create a custom "mkPoetryApplication" API function that under the hood uses
        # the packages and versions (python3, poetry etc.) from our pinned nixpkgs above:
        inherit (poetry2nix.lib.mkPoetry2Nix { inherit pkgs; }) mkPoetryApplication;
      in
      {
        packages = {
          app = mkPoetryApplication {
            packageName = "app";
            projectDir = ./.;
          };

          default = self.packages.${system}.app;
        };
      }
    );
}

In reply to @ericadelagnier:multi.coop
the build works ! thank you :) I can now run the app with ./result/bin/hello, but I'm not sure how to call it with gunicorn ? the README suggest "./result/bin/gunicorn web:app" but I'm not sure how to make gunicorn available in the result

I would suggest to add gunicorn in flake.nix buildInputs, and run it from python something like subprocess.Popen(["gunicorn", "web:app""])

Part of flake.nix with buildInputs:

packages = {
  app = mkPoetryApplication {
    packageName = "app";
    projectDir = ./.;
  };

  buildInputs = with pkgs; [
    python312Packages.gunicorn
  ];

  default = self.packages.${system}.app;
};

In reply to @ericadelagnier:multi.coop
the build works ! thank you :) I can now run the app with ./result/bin/hello, but I'm not sure how to call it with gunicorn ? the README suggest "./result/bin/gunicorn web:app" but I'm not sure how to make gunicorn available in the result

I would suggest to add gunicorn in flake.nix buildInputs, and run it from python something like subprocess.Popen(["gunicorn", "web:app"])

Part of flake.nix with buildInputs:

packages = {
  app = mkPoetryApplication {
    packageName = "app";
    projectDir = ./.;
  };

  buildInputs = with pkgs; [
    python312Packages.gunicorn
  ];

  default = self.packages.${system}.app;
};