anchor.diff: -{ stdenv, buildPythonPackage, fetchPypi, numpy, future, spglib, glibcLocales }:
  +{ stdenv, buildPythonPackage, fetchPypi, numpy, future, spglib, glibcLocales, pytest }:
   
   buildPythonPackage rec {
     pname = "seekpath";
  
positive.code: 
    nativeBuildInputs = [ glibcLocales ];
  
    meta = with stdenv.lib; {
      description = "A module to obtain and visualize band paths in the Brillouin zone of crystal structures.";
      homepage = https://github.com/giovannipizzi/seekpath;
      license = licenses.mit;
      maintainers = with maintainers; [ psyanticy ];
    };
  
negative.code:   src = fetchPypi {
      inherit pname version;
      sha256 = "b61dadba82acc0838402981b7944155adc092b114ca81f53f61b1d498a512e3a";
    };
  
    LC_ALL = "en_US.utf-8";
  
  