Try rm -rf instead of FileUtils.rm_rf
FileUtils.rm_rf started to randomly fail on http://ci.rvm.jp/results/trunk-mjit@phosphorus-docker since around https://github.com/ruby/fileutils/pull/99.
Try rm -rf instead of FileUtils.rm_rf
FileUtils.rm_rf started to randomly fail on http://ci.rvm.jp/results/trunk-mjit@phosphorus-docker
since around https://github.com/ruby/fileutils/pull/99.