CSV出力エラー - Githubissues

初めて利用させていただいています。
CSV出力させようと -t csv オプションで実行したところ、以下のエラーが出ました。ruby勉強し始めたばかりで、Rakefile見てもわからなかったのですが、原因に心当たりありますでしょうか。
CSV以外(ASCII Art、md)は出力できています。

環境

$ cat /etc/centos-release
CentOS Linux release 7.9.2009 (Core)
$ ruby -v
ruby 2.5.5p157 (2019-03-15 revision 67260) [x86_64-linux]
$ which ruby
/opt/rh/rh-ruby25/root/usr/bin/ruby

ログ
```
...(serverspec original log)
```

description,,,,result vtm/base@vtm01(192.168.120.2),,,, ,File "/var/log/vario",,, ,,is expected to be directory,,OK ,,is expected to be owned by "root",,OK ,,is expected to be grouped into "root",,OK ,,is expected to be mode 755,,OK ,File "/etc/sysconfig/network-scripts/route-eth0",,, ,,is expected to be file,,OK ,,is expected to be owned by "root",,OK ,,is expected to be grouped into "root",,OK ,,is expected to be mode 644,,OK ,Routing Table,,, Traceback (most recent call last): 28: from /home/h.nakano/bin/serverspec-runner:23:in <main>' 27: from /home/h.nakano/bin/serverspec-runner:23:inload' 26: from /home/h.nakano/.gem/ruby/gems/serverspec-runner-1.3.8/bin/serverspec-runner:98:in <top (required)>' 25: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:188:ininvoke' 24: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:199:in invoke_with_call_chain' 23: from /opt/rh/rh-ruby25/root/usr/share/ruby/monitor.rb:226:inmon_synchronize' 22: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:218:in block in invoke_with_call_chain' 21: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:241:ininvoke_prerequisites' 20: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:241:in each' 19: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:243:inblock in invoke_prerequisites' 18: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:199:in invoke_with_call_chain' 17: from /opt/rh/rh-ruby25/root/usr/share/ruby/monitor.rb:226:inmon_synchronize' 16: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:218:in block in invoke_with_call_chain' 15: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:241:ininvoke_prerequisites' 14: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:241:in each' 13: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:243:inblock in invoke_prerequisites' 12: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:199:in invoke_with_call_chain' 11: from /opt/rh/rh-ruby25/root/usr/share/ruby/monitor.rb:226:inmon_synchronize' 10: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:219:in block in invoke_with_call_chain' 9: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:281:inexecute' 8: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:281:in each' 7: from /home/h.nakano/.gem/ruby/gems/rake-13.0.3/lib/rake/task.rb:281:inblock in execute' 6: from /home/h.nakano/.gem/ruby/gems/serverspec-runner-1.3.8/Rakefile:240:in block (2 levels) in <top (required)>' 5: from /opt/rh/rh-ruby25/root/usr/share/ruby/csv.rb:1141:inforeach' 4: from /opt/rh/rh-ruby25/root/usr/share/ruby/csv.rb:1289:in open' 3: from /opt/rh/rh-ruby25/root/usr/share/ruby/csv.rb:1142:inblock in foreach' 2: from /opt/rh/rh-ruby25/root/usr/share/ruby/csv.rb:1764:in each' 1: from /home/h.nakano/.gem/ruby/gems/serverspec-runner-1.3.8/Rakefile:241:inblock (3 levels) in <top (required)>' /home/h.nakano/.gem/ruby/gems/serverspec-runner-1.3.8/Rakefile:241:in `*': negative argument (ArgumentError)

hiracy / serverspec-runner

CSV出力エラー #48