Fix building using native extensions

iNecas · iNecas · commit 06b11c5bc8f7 · 2015-06-15T17:33:30.000+02:00
diff --git a/ext/concurrent/extconf.rb b/ext/concurrent/extconf.rb
@@ -1,5 +1,6 @@
 require 'fileutils'
 
+$:.unshift(File.expand_path('../../../lib', __FILE__))
 require 'concurrent/utility/native_extension_loader'
 
 EXTENSION_NAME = 'extension'
