Issue #3666 has been updated by Luis Lavena. Hello, Mr. Nobuyoshi Nakada and Shyouhei Urabe, Can you check the patch contents and see if they could be applied. Again, this is not a 64bits patch, is just an update definition of MinGW headers manually backported from r26311 Thank you. ---------------------------------------- http://redmine.ruby-lang.org/issues/show/3666 ---------------------------------------- http://redmine.ruby-lang.org