Shelljs deletes OLDPWD env variable which creates error with webpack

[joker-777]

Hi, we use your library in our webpack configuration file and we saw that the library shelljs which you use deletes the env variable OLDPWD which creates the error

ERROR in EnvironmentPlugin - OLDPWD environment variable is undefined.

You can pass an object with default values to suppress this warning.
See https://webpack.js.org/plugins/environment-plugin for example.

I also created an issue for shelljs.