Describe the bug

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What is the current behavior?
when I run webpack --mode development(or production), the webpack-cli shows TypeError: Cannot read property 'length' of undefined on the line node_modules\webpack-cli\bin\cli.js:93. my computer is win10

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To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

1.just create a folder on win10
2.npm i -S webpack@next
3.npm i -S webpack-cli@latest
4.write "dev": "webpack --mode development" in package.json
5.npm run dev

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Please paste the results of webpack-cli info here, and mention other relevant information

Additional context
Add any other context about the problem here like linking to an similar issue you might think is the cause.