DefinePlugin: "Conflicting values for 'process.env'" if you have a .env file

[jdelStrother]

Describe the bug
If you have a .env file present in the cwd, it causes a warning to be emitted:

WARNING in DefinePlugin
Conflicting values for 'process.env'

To Reproduce
Checkout https://github.com/jdelStrother/conflicting-process-env
Run yarn
Run yarn start-storybook --smoke-test

System

Environment Info:

  System:
    OS: macOS 11.5.2
    CPU: (8) arm64 Apple M1
  Binaries:
    Node: 16.2.0 - ~/.nix-profile/bin/node
    Yarn: 1.22.10 - ~/.nix-profile/bin/yarn
    npm: 7.13.0 - ~/.nix-profile/bin/npm
  npmPackages:
    @storybook/addon-actions: ^6.3.7 => 6.3.7
    @storybook/addon-essentials: ^6.3.7 => 6.3.7
    @storybook/addon-links: ^6.3.7 => 6.3.7
    @storybook/addon-storyshots: ^6.3.7 => 6.3.7
    @storybook/builder-webpack5: ^6.3.7 => 6.3.7
    @storybook/core: ^6.3.7 => 6.3.7
    @storybook/manager-webpack5: ^6.3.7 => 6.3.7
    @storybook/react: ^6.3.7 => 6.3.7
    @storybook/theming: ^6.3.7 => 6.3.7

Additional context

When running storybook interactively, one can just ignore this warning. However, it does cause start-storybook --smoke-test to fail, which is annoying for CI purposes. I don't actually want my .env file loaded in storybook, but can't see a good way of preventing the automatic detection.

[usrrname]

Hey jdelStrother, thanks for filing this issue! I think adding the webpack5 tag too to bring it to the core team's attention.

I've been experiencing the same issue while using sb@6.3.7 with node 14.17.0
Also looked at #14257 and used these suggested resolutions in my package.json to get it running locally.

Environment Info:

  System:
    OS: macOS 11.5.2
    CPU: (8) x64 Intel(R) Core(TM) i5-1038NG7 CPU @ 2.00GHz
  Binaries:
    Node: 14.17.0 - ~/.nvm/versions/node/v14.17.0/bin/node
    Yarn: 1.22.5 - ~/.yarn/bin/yarn
    npm: 6.14.13 - ~/.nvm/versions/node/v14.17.0/bin/npm
  Browsers:
    Chrome: 92.0.4515.159
    Safari: 14.1.2
  npmPackages:
    @storybook/addon-a11y: ^6.3.7 => 6.3.7 
    @storybook/addon-actions: ^6.3.7 => 6.3.7 
    @storybook/addon-docs: ^6.3.7 => 6.3.7 
    @storybook/addon-essentials: ^6.3.7 => 6.3.7 
    @storybook/addon-jest: ^6.3.7 => 6.3.7 
    @storybook/addon-links: ^6.3.7 => 6.3.7 
    @storybook/addon-storyshots: ^6.3.7 => 6.3.7 
    @storybook/addon-storyshots-puppeteer: ^6.3.7 => 6.3.7 
    @storybook/addon-viewport: ^6.3.7 => 6.3.7 
    @storybook/builder-webpack5: ^6.3.7 => 6.3.7 
    @storybook/manager-webpack5: ^6.3.7 => 6.3.7 
    @storybook/react: ^6.3.7 => 6.3.7 
    @storybook/testing-react: 0.0.22 => 0.0.22 
    @storybook/theming: ^6.3.7 => 6.3.7 

main.ts:

import path from 'path';
import 'dotenv';
import { BabelConfig } from 'ts-jest/dist/types';

module.exports = {
  stories: ['../src/**/*.stories.@(jsx|tsx|mdx)'],
  addons: [
    '@storybook/addon-links',
    '@storybook/addon-docs',
    'storybook-addon-designs', // https://storybook.js.org/addons/storybook-addon-designs
    '@storybook/addon-essentials',
    '@storybook/addon-jest',
    '@storybook/addon-storyshots',
    '@storybook/addon-a11y',
    '@storybook/addon-viewport/register',
    'storybook-addon-gatsby',
  ],
  core: {
    builder: 'webpack5',
  },
  typescript: {
    check: true,
  },
  babel: async (options: BabelConfig) => {
    return {
      ...options,
    };
  },
  webpackFinal: async (config: any) => {
    config.module.rules[0].exclude = [/node_modules\/(?!(gatsby)\/)/];

    config.output = {
      path: path.join(__dirname, '../dist'),
      publicPath: '/',
      filename: 'static/js/[name].js',
      chunkFilename: 'static/js/[name].chunk.js',
    };

    config.resolve.fallback = {
      crypto: false,
      path: require.resolve('path-browserify'),
      assert: require.resolve('assert-browserify'),
    };

    // Return the altered config
    return config;
  },
};

I did also notice that a local dev with start-storybook "completes" at 99%... ( ͡° ʖ̯ ͡°)

[shilman]

Ta-da!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.4.0-alpha.34 containing PR #15925 that references this issue. Upgrade today to the @next NPM tag to try it out!

npx sb upgrade --prerelease

Closing this issue. Please re-open if you think there's still more to do.