error.c: rb_write_error_str
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
error.c: rb_write_error_str
rb_write_error_str() instead of writing to rb_stderr directly.
warning from require seems to still have race condition errors.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e