anchor.diff:      platforms = platforms.linux;
     };
   }
  -
  
positive.code:   src = fetchFromGitLab {
      owner = "Molcas";
      repo = "OpenMolcas";
      rev = gitLabRev;
      sha256 = "0cap53gy1wds2qaxbijw09fqhvfxphfkr93nhp9xdq84yxh4wzv6";
    };
  
  
negative.code: 
    cmakeFlags = [
      "-DOPENMP=ON"
      "-DTOOLS=ON"
      "-DHDF5=ON"
      "-DFDE=ON"
      "-DWFA=ON"
      "-DCTEST=ON"
      "-DCHEMPS2=ON" "-DCHEMPS2_DIR=${chemps2}/bin"
    ] ++ lib.lists.optionals (blas-i8.passthru.implementation == "openblas") [ "-DOPENBLASROOT=${blas-i8.passthru.provider.dev}" "-DLINALG=OpenBLAS" ]
      ++ lib.lists.optionals (blas-i8.passthru.implementation == "mkl") [ "-DMKLROOT=${blas-i8.passthru.provider}" "-DLINALG=MKL"]
    ;
  
    postConfigure = ''
      # The Makefile will install pymolcas during the build grrr.
  