Port of upstream patch https://github.com/rubygems/rubygems/pull/2457 Since r65470 (Upstream: https://github.com/rubygems/rubygems/pull/2441), builds of extension gem had always failed under really_verbose mode. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e