safe_VimDebug.vim.patch

--- VimDebug.vim	2013-05-25 22:57:31.000000000 +0000
+++ ~/.vim/plugin/VimDebug.vim	2015-12-04 20:46:43.000000000 +0000
@@ -8,10 +8,15 @@
 if (!has('perl') || !has('signs'))
    echo "VimDebug requires +perl and +signs"
    finish
 endif
 
+perl eval 'use Vim::Debug'; $r=$@?0:1; VIM::DoCommand("let foundVimDebug = $r");
+if (foundVimDebug == 0)
+	finish
+endif
+
 " --------------------------------------------------------------------
 " Configuration variables.
 
 " Make sure all the values remain coherent if you change any.