anchor.diff:      case "$OSTYPE" in
         linux*)   exec "$(dirname "$0")/linux/tttool" "$@" ;;
         darwin*)  exec "$(dirname "$0")/osx/tttool" "$@" ;;
  -      msys*)    echo "$(dirname "$0")/tttool.exe" "$@" ;;
  -      cygwin*)  echo "$(dirname "$0")/tttool.exe" "$@" ;;
  +      msys*)    exec "$(dirname "$0")/tttool.exe" "$@" ;;
  +      cygwin*)  exec "$(dirname "$0")/tttool.exe" "$@" ;;
         *)        echo "unsupported operating system $OSTYPE" ;;
       esac
     '';
  
positive.code:     '';
    };
  
  in
  
  let
  
negative.code:   windows-exe = tttool-exe pkgs-windows;
    static-exe = tttool-exe pkgs-static;
    osx-exe = tttool-exe pkgs-osx;
    osx-exe-bundle = osx-bundler pkgs-osx osx-exe;
  
    macdylibbundler = pkgs.macdylibbundler;
  
    # playmus-static = playmus-exe pkgs-static;
    # playmus-windows = playmus-exe pkgs-windows;
  