anchor.diff:          wrapProgram "$out/bin/git-svn"                  \
                        --set GITPERLLIB "$gitperllib"     \
                        --prefix PATH : "${subversion}/bin" ''
  -       else ''
  -       echo "NOT installing \`git-svn' since \`svnSupport' is false."
  -       rm $out/bin/git-svn '')
  +       else '' # replace git-svn by notification script
  +        notSupported $out/bin/git-svn "reinstall with config git = { svnSupport = true } set"
  +       '')
   
      + ''# Install man pages and Info manual
          make PERL_PATH="${perl}/bin/perl" cmd-list.made install install-info \
  
positive.code: 
    postInstall =
      ''
        # Install Emacs mode.
        echo "installing Emacs mode..."
        ensureDir $out/share/emacs/site-lisp
  
negative.code:                      --set TK_LIBRARY "${tk}/lib/tk8.4" \
                       --prefix PATH : "${tk}/bin"
         done
       '' else ''
        # don not wrap Tcl/Tk, replace them by notification scripts
         for prog in gitk git-gui git-citool
         do
           notSupported "$out/bin/$prog" "reinstall with config git = { guiSupport = true } set"
         done
       '')
  
     + ''# Wrap `git-clone'
         wrapProgram $out/bin/git-clone                   \
  