Building Python project "mimir": Directory '.' is not installable. Neither 'setup.py' nor 'pyproject.toml' found

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1

I’m trying to package the Python3 package mimir in Nix. I used the wiki and other derivations from nixpkgs. I think I’m close to finish, but unfortunately, the build fails with

Directory ‘.’ is not installable. Neither ‘setup.py’ nor ‘pyproject.toml’ found

To be more specific, it fails in the pipBuildPhase:

image
image1654×300 43.5 KB

The wiki’s guidelines to cope with that error, i.e., setting format = "pyproject" didn’t help.

For simplicity, I’ve created a standalone nix file:

let 
  # nixpkgs 23.05
  pkgs = import <nixpkgs> { };
  mimirSrc = builtins.fetchTarball {
    url = "https://github.com/simon-stahlberg/mimir/archive/refs/heads/main.tar.gz";
    sha256 = "sha256:1hdmcr404wrx5wdf32gg0jiv2wh4wfg9gxgc22z2vx622pjzb3dw";
  };
  pybind11-stubgenSrc = builtins.fetchTarball {
    url = "https://github.com/sizmailov/pybind11-stubgen/archive/refs/heads/master.tar.gz";
    sha256 = "sha256:1pzn698jcfb6sa7gbmmj9ynx84rlb628ixrb3fxy4h8sx76hvbpl";
  };
  pybind11-stubgen = pkgs.python3Packages.buildPythonPackage {
    name = "pybind11-stubgen";
    src = pybind11-stubgenSrc;
    format = "setuptools";
  };
in
pkgs.python3Packages.buildPythonPackage {
  name = "mimir";
  src = mimirSrc;
  format = "pyproject";
  nativeBuildInputs = [
    pkgs.cmake
    pkgs.gnumake
    pkgs.python3Packages.pybind11
    pybind11-stubgen
  ];
  buildInputs = [
    pkgs.boost
    pkgs.python3Packages.pybind11
    pkgs.gtest
  ];
  doCheck = false;
  # dontUseCmakeConfigure = true;
}

What am I missing?

If I add dontUseCmakeConfigure = true, the build succeeds and I see the following:
image

However, I was expecting a binary to appear and not just a shared object.