Poetry2nix and pycairo

Help
1

Hello! I’m in the final stretch of getting a development environment up and running with cairo, but mkPoetryEnv is failing when it tries to build pycairo with ninja. Any help or advice would be much appreciated.

It’s a wierd one for me, as the shell environment built, and I was able to poetry add pycairo and import it to ipython, but then when I exited the shell re-ran it later, it fails.

I based my shell.nix on the flake from this post here. My error looks like this:

source root is pycairo-1.24.0
setting SOURCE_DATE_EPOCH to timestamp 1687160849 of file pycairo-1.24.0/setup.cfg
patching sources
configuring
no configure script, doing nothing
building
build flags: -j4
ninja: error: loading 'build.ninja': No such file or directory
error: builder for '/nix/store/2kjdbsj2719yak5wxga0j1kq1z7kb2pr-python3.11-pycairo-1.24.0.drv' failed with exit code 1;
       last 10 log lines:
       > unpacking sources
       > unpacking source archive /nix/store/v2kinyrcs3mh4jpwnq9z32727jjp43br-pycairo-1.24.0.tar.gz
       > source root is pycairo-1.24.0
       > setting SOURCE_DATE_EPOCH to timestamp 1687160849 of file pycairo-1.24.0/setup.cfg
       > patching sources
       > configuring
       > no configure script, doing nothing
       > building
       > build flags: -j4
       > ninja: error: loading 'build.ninja': No such file or directory
       For full logs, run 'nix log /nix/store/2kjdbsj2719yak5wxga0j1kq1z7kb2pr-python3.11-pycairo-1.24.0.drv'.
error: 1 dependencies of derivation '/nix/store/iz2j8g1bh7qvvx6jfq7bsrdh0jwcr9cc-python3-3.11.1-env.drv' failed to build

And my shell.nix so far is this:

{ pkgs ? import <nixpkgs> {} }:

let

  poetryEnv = pkgs.poetry2nix.mkPoetryEnv {
    projectDir = ./.;
    preferWheels = true;
    python = pkgs.python311;
    overrides = pkgs.poetry2nix.overrides.withDefaults (self: super: {
      pycairo = super.pycairo.overridePythonAttrs (
        old: {
          nativeBuildInputs = [
            self.meson
            pkgs.buildPackages.ninja
            pkgs.buildPackages.pkg-config
            pkgs.ninja
            # pkgs.cairo
            # pkgs.gtk3
          ];
          propogatedBuildInputs = [ pkgs.cairo ];
        }
      );
      pygobject = super.pygobject.overridePythonAttrs (
        old: {
          buildInputs = (old.buildInputs or [ ]) ++ [ super.setuptools ];
        }
      );
      overrides = super.overrides.overridePythonAttrs (
        old: {
          buildInputs = (old.buildInputs or [ ]) ++ [ super.setuptools ];
        }
      );
      attrs = super.attrs.overridePythonAttrs (
        old: {
          buildInputs = (old.buildInputs or []) ++ [ super.hatchling ];
        });
    });
  };
  
in
  pkgs.mkShell {
    nativeBuildInputs = [
      pkgs.python311
      ( pkgs.poetry.override { python = pkgs.python311; } )
      pkgs.pandoc
      pkgs.cairo
      pkgs.pkg-config
      # pkgs.python311Packages.gst-python
      pkgs.gobject-introspection
      pkgs.exa
      pkgs.gtk3-x11
      pkgs.fd
      poetryEnv
    ];
    shellHook = '' 
      export XDG_DATA_DIRS=$GSETTINGS_SCHEMA_PATH
      SOURCE_DATE_EPOCH=$(date +%s)
      alias jn="jupyter notebook"
      alias ls=exa
      alias find=fd 
    '';
  }
2

I tried building ninja with certain flags, like below, but unfortunately, that tries to download ninja source from github in a derivation, and apparently there’s no network access allowed.

  python = pkgs.python3;
  ninja = python.pkgs.buildPythonPackage {
    pname = "ninja";
    version = "1.11.1";

    src = python.pkgs.fetchPypi {
      pname = "ninja";
      version = "1.11.1";
      # sha256 = "sha256-yDOkfTmy0e7j+cqIb6FYHv1b5gaLgnNKwimWHuh0j5A=";
      sha256 = "sha256-yDOkfTmy0e7j+cqIb6FYHv1b5gaLgnNKwimWHuh0j5A=";
    };

    nativeBuildInputs = [
      python.pkgs.scikit-build
      python.pkgs.setuptools_scm
      python.pkgs.setuptools
      pkgs.cmake
    ];
    format = "other";
    # dontUseCmakeConfigure = true;
    
  };
3

I’m facing the same problem, were you able to understand it?
I noticed that:

  1. a nix build nixpkgs#python311Packages.pycairo works without problems
  2. if I explicitly pin pycairo to 1.23.0 in the pyproject.toml, and not using 1.24.0 coming from nixpkgs, it gets built correctly