Only fixup bundler when needed, and only once.

lib/geminabox.rb

@@ -7,7 +7,6 @@
 
 require 'hostess'
 
-
 class Geminabox < Sinatra::Base
   enable :static, :methodoverride
 
@@ -21,6 +20,12 @@ class << self
     def disallow_replace?
       ! allow_replace
     end
+
+    def fixup_bundler_rubygems!
+      return if @post_reset_hook_applied
+      Gem.post_reset{ Gem::Specification.all = nil } if defined? Bundler and Gem.respond_to? :post_reset
+      @post_reset_hook_applied = true
+    end
   end
 
   autoload :GemVersionCollection, "geminabox/gem_version_collection"
@@ -96,7 +101,7 @@ def error_response(code, message)
   end
 
   def reindex
-    Gem.post_reset{ Gem::Specification.all = nil }
+    Geminabox.fixup_bundler_rubygems!
     Gem::Indexer.new(options.data).generate_index
   end