--- ruby-1.9.3-p286/test/ruby/test_io.rb.devtty	2012-10-12 17:37:54.000000000 +0900
+++ ruby-1.9.3-p286/test/ruby/test_io.rb	2012-10-13 14:00:24.000000000 +0900
@@ -2068,6 +2068,11 @@
     return if /linux/ !~ RUBY_PLATFORM
     return if /^i.?86|^x86_64/ !~ RUBY_PLATFORM
     return unless File.exist?('/dev/tty')
+    begin
+      File.open('/dev/tty') {|f|}
+    rescue Errno::ENXIO
+      return
+    end
 
     File.open('/dev/tty') { |f|
       tiocgwinsz=0x5413