OS: Linux (Ubuntu 14.10)
Listen version: 3.03

Minimal test case:

mkdir dir
ln -s dir dir2
ruby -e "require 'listen'; Listen.to('.').start"

        ** ERROR: directory is already being watched! **

        Directory: [path]/dir

        is already begin watched through: [path]/dir

        MORE INFO: https://github.com/guard/listen/wiki/Duplicate-directory-errors

My use case is that I would like to use spring-watcher-listen + Listen 3.0 in a Rails project containing several local symlinks which cannot be removed. Since #273, running Listen spams standard error with the above verbose text for what is a benign and extremely common scenario.

For my case, my workaround for now is to silence the SymlinkDetector with this monkey-patch:

require 'listen/record/symlink_detector'
module Listen
  class Record
    class SymlinkDetector
      def _fail(_, _)
        fail Error, "Don't watch locally-symlinked file twice"
      end
    end
  end
end

I agree with the discussion in #273 that distinguishing between (harmless) local symlinks and (problematic) filesystem loops would be the 'Best solution' for this issue, as I believe that the current implementation throws out the baby with the bathwater, so to speak. As long as the 'Best' implementation remains a 'pointless waste of time', would it at least be possible to add an opt-in mechanism for suppressing this verbose ERROR message so that the local symlink warning could be suppressed without requiring this patch?