anchor.diff:  
     services.khd.enable = true;
   
  +  launchd.user.agents.fetch-nixpkgs = {
  +    command = "${pkgs.git}/bin/git -C ~/.nix-defexpr/nixpkgs fetch origin master";
  +    environment.GIT_SSL_CAINFO = "${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt";
  +    serviceConfig.KeepAlive = false;
  +    serviceConfig.ProcessType = "Background";
  +    serviceConfig.StartInterval = 60;
  +  };
  +
     services.activate-system.enable = true;
     services.nix-daemon.enable = true;
     services.nix-daemon.tempDir = "/nix/tmp";
  
positive.code:     set bg=dark
  
      set clipboard=unnamed
  
      vmap s S
  
      cnoremap %% <C-r>=expand('%:h') . '/'<CR>
  
      let mapleader = ' '
      nnoremap <Leader>p :FZF<CR>
      nnoremap <silent> <Leader>e :exe 'FZF ' . expand('%:h')<CR>
  
      set backup
      set backupdir=~/.vim/tmp/backup//
  
negative.code:     if !isdirectory(expand(&directory))
        call mkdir(expand(&directory), "p")
      endif
  
      vmap s S
  
      cnoremap %% <C-r>=expand('%:h') . '/'<CR>
  
      let mapleader = ' '
      nnoremap <Leader>p :FZF<CR>
      nnoremap <silent> <Leader>e :exe 'FZF ' . expand('%:h')<CR>
  
      function! s:ag_to_qf(line)
        let parts = split(a:line, ':')
        return {'filename': parts[0], 'lnum': parts[1], 'col': parts[2],
              \ 'text': join(parts[3:], ':')}
      endfunction
  
      function! s:ag_handler(lines)
        if len(a:lines) < 2 | return | endif
  
        let cmd = get({'ctrl-x': 'split',
              \ 'ctrl-v': 'vertical split',
              \ 'ctrl-t': 'tabe'}, a:lines[0], 'e')
        let list = map(a:lines[1:], 's:ag_to_qf(v:val)')
  
        let first = list[0]
        execute cmd escape(first.filename, ' %#\')
        execute first.lnum
        execute 'normal!' first.col.'|zz'
  
        if len(list) > 1
          call setqflist(list)
          copen
          wincmd p
        endif
      endfunction
  
      command! -nargs=* Ag call fzf#run({
            \ 'source':  printf('${pkgs.ag}/bin/ag --nogroup --column --color "%s"',
            \                   escape(empty(<q-args>) ? '^(?=.)' : <q-args>, '"\')),
            \ 'sink*':   function('<sid>ag_handler'),
            \ 'options': '--ansi --expect=ctrl-t,ctrl-v,ctrl-x --delimiter : --nth 4.. '.
            \            '--multi --bind ctrl-a:select-all,ctrl-d:deselect-all '.
            \            '--color hl:68,hl+:110',
            \ 'down':    '50%' })
  
      let g:syntastic_always_populate_loc_list = 1
      let g:ycm_seed_identifiers_with_syntax = 1
    '';
  
    programs.zsh.enable = true;
  