Why doesn't webpack-dev-server see ./src?

Question

webpack

The structure is:
-frontend
--webpack.config.js
--src
-package.json
In package.json I have a command:

"start-frontend": "webpack-dev-server --mode development --open --hot --content-base ./frontend",

When it starts it gives:

ERROR in multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./src
Module not found: Error: Can't resolve './src' in '/Users/shchypylov/Documents/projects/playground/sell_fullstack'
 @ multi (webpack)-dev-server/client?http://localhost:8080 webpack/hot/dev-server ./src
ℹ ｢wdm｣: Failed to compile.

Why?