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Description

gatsby develop doesn't work because of an error #98123 from Webpack.

Steps to reproduce

1. Clone my repo
2. cd into that repo
3. Run npm install
4. Run gatsby develop

Expected result

Development server should start

Actual result

I get this output:

ERROR #98123  WEBPACK
Generating SSR bundle failed
[BABEL] /home/fw33n/ateliers-chartreux/.cache/develop-static-entry.js: Cannot find module '@babel/helper-create-class-features-plugin' (While processing: "/home/fw33n/ateliers-chartreux/node_modules/@babel/plugin-proposal-class-properties/lib/index.js")
File: .cache/develop-static-entry.js
⠼ start webpack server

Environment

gatsby info --clipboard (I'm running Ubuntu in WSL):

System:
  OS: Linux 4.4 Ubuntu 18.04.2 LTS (Bionic Beaver)
  CPU: (8) x64 Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz
  Shell: 4.4.19 - /bin/bash
Binaries:
  Node: 10.16.3 - ~/.nvm/versions/node/v10.16.3/bin/node
  npm: 6.11.3 - ~/.nvm/versions/node/v10.16.3/bin/npm
Languages:
  Python: 2.7.15+ - /usr/bin/python
npmPackages:
  gatsby: ^2.15.9 => 2.15.9
  gatsby-plugin-sass: ^2.1.13 => 2.1.13
  gatsby-source-contentful: ^2.1.33 => 2.1.33
npmGlobalPackages:
  gatsby-cli: 2.7.47

Additionnally, my package.json:

{
  "name": "ateliers-chartreux",
  "private": true,
  "description": "Le site des Ateliers Chartreux",
  "version": "0.1.0",
  "license": "MIT",
  "scripts": {
    "build": "gatsby build",
    "develop": "gatsby develop",
    "format": "prettier --write \"**/*.{js,jsx,json,md}\"",
    "start": "npm run develop",
    "serve": "gatsby serve",
    "test": "echo \"Write tests! -> https://gatsby.dev/unit-testing \""
  },
  "dependencies": {
    "gatsby": "^2.15.9",
    "gatsby-plugin-sass": "^2.1.13",
    "gatsby-source-contentful": "^2.1.33",
    "node-sass": "^4.12.0",
    "react": "^16.9.0",
    "react-dom": "^16.9.0"
  },
  "devDependencies": {
    "prettier": "^1.18.2"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/gatsbyjs/gatsby-starter-hello-world"
  },
  "bugs": {
    "url": "https://github.com/gatsbyjs/gatsby/issues"
  }
}

npm run develop will get you up & running for now.