* io.c (io_fillbuf): show fd number on failure to debug.
  http://c5632.rubyci.org/~chkbuild/ruby-trunk/log/20130316T050302Z.diff.html.gz

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39803 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-03-18

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39804 b2dd03c8-39d4-4d8f-98ff-823fe69b080e