anchor.diff:    propagatedBuildInputs = [
       astropy
       astropy-healpix
  -    astropy-helpers
       numpy
       scipy
     ];
  
positive.code:     pytestCheckHook
    ];
  
    preCheck = ''
      cd build/lib*
    '';
  
    pythonImportsCheck = [
      "reproject"
  
negative.code: 
    nativeBuildInputs = [
      astropy-extension-helpers
      cython
      setuptools-scm
    ];
  