class variable. use test/unit instead of minitest/autorun. dispose `Interrupted system call' error messages at parallel test. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40630 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
class variable. use test/unit instead of minitest/autorun. dispose `Interrupted system call' error messages at parallel test. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40630 b2dd03c8-39d4-4d8f-98ff-823fe69b080e