一部のserverでerrorは出る。
が解決策としてnetで書かれているようなバージョンを下げるのはやりたくない。
alertなので、そのままにする。

[PM2] Starting /opt/nodejs/108/index.js in fork_mode (1 instance)
(node:3628241) Warning: Accessing non-existent property 'cat' of module exports inside circular dependency
(Use `node --trace-warnings ...` to show where the warning was created)
(node:3628241) Warning: Accessing non-existent property 'cd' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'chmod' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'cp' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'dirs' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'pushd' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'popd' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'echo' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'tempdir' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'pwd' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'exec' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'ls' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'find' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'grep' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'head' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'ln' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'mkdir' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'rm' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'mv' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'sed' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'set' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'sort' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'tail' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'test' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'to' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'toEnd' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'touch' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'uniq' of module exports inside circular dependency
(node:3628241) Warning: Accessing non-existent property 'which' of module exports inside circular dependency
[PM2] Done.