anchor.diff:    '';
   
     buildInputs = [
  -    openal curl libogg libvorbis SDL2 SDL2_image zlib
  +    openal curl libogg libvorbis libtheora SDL2 SDL2_image zlib clang
     ];
   
     NIX_CFLAGS_COMPILE = [
  
positive.code: 
    enableParallelBuilding = true;
  
    makeFlags = [ "OPT=true"
                  "RELEASE=true"
                  "DATA_DIR=$(out)/share"
                  "ENABLE_LOCAL_USER_DIR=true"
                ];
  
    installPhase = ''
      install -Dm755 keeper $out/bin/keeper
  
negative.code: 
        "nix-prefetch-url file://\$PWD/${name}".
      '';
      sha256 = "0115pxdzdyma2vicxgr0j21pp82gxdyrlj090s8ihp0b50f0nlll";
    } else null;
  
    sourceRoot = "source";
  