anchor.diff:  
     src = fetchurl {
       url = "mirror://sourceforge/${name}/${name}-${version}.tar.gz";
  -    sha256 = "0x0n81z0s4pl8nwpf7ivlsbvsdphm9w42250g7qdkizl0132by6s";
  +    sha256 = "0kdncy6137sg3rradirxzj10mkcvafxd892zlclwhr9sa7b12zhn";
     };
   
     buildInputs = stdenv.lib.filter (x: x != null) [
       sbcl ecl texinfo perl python makeWrapper
  +    gnuplot   # required in the test suite
     ];
   
     postInstall = ''
  
positive.code: 
  let
    name    = "maxima";
    version = "5.41.0";
  
    searchPath =
      stdenv.lib.makeBinPath
  
negative.code:     ./known-ecl-failures.patch
    ];
  
    # The test suite is disabled since 5.42.2 because of the following issues:
    #
    #   Errors found in /build/maxima-5.42.2/share/linearalgebra/rtest_matrixexp.mac, problems:
    #   (20 21 22)
    #   Error found in rtest_arag, problem:
    #   (error break)
    #   3 tests failed out of 3,881 total tests.
    #
    # These failures don't look serious. It would be nice to fix them, but I
    # don't know how and probably won't have the time to find out.
    doCheck = false;    # try to re-enable after next version update
  
    enableParallelBuilding = true;
  
  