system_bindir

# File lib/bundler.rb, line 341
    def system_bindir
      # Gem.bindir doesn't always return the location that RubyGems will install
      # system binaries. If you put '-n foo' in your .gemrc, RubyGems will
      # install binstubs there instead. Unfortunately, RubyGems doesn't expose
      # that directory at all, so rather than parse .gemrc ourselves, we allow
      # the directory to be set as well, via `bundle config bindir foo`.
      Bundler.settings[:system_bindir] || Bundler.rubygems.gem_bindir
    end