“webpack dev_server configuration not found“ error during production build

[phacks]

Hi folks!

I’m hitting an error in Heroku CI that prevents the assets build:

Compilation failed:
yarn run v1.22.10
$ ./bin/webpack-dev-server --config /tmp/build_706ee277_/config/webpack/production.js
webpack dev_server configuration not found in /tmp/build_706ee277_/config/webpacker.yml[production].
Please run bundle exec rails webpacker:install to install Webpacker

The error makes sense insofar as there is no dev_server configuration for the production environment (and there shouldn’t be), but I don’t know why it even tries to look it up and run the dev server in the first place.

Webpacker is installed (I have all the bin/ and the configs), I’m running [email protected], and here’s my config/webpacker.yml:

config/webpacker.yml, click to expand

# Note: You must restart bin/webpack-dev-server for changes to take effect

default: &default
  source_path: app/javascript
  source_entry_path: packs
  public_root_path: public
  public_output_path: packs
  cache_path: tmp/cache/webpacker
  check_yarn_integrity: false
  webpack_compile_output: true

  # Additional paths webpack should lookup modules
  # ['app/assets', 'engine/foo/app/assets']
  resolved_paths: ["app/components"]

  # Reload manifest.json on all requests so we reload latest compiled packs
  cache_manifest: false

  # Extract and emit a css file
  extract_css: false

  static_assets_extensions:
    - .jpg
    - .jpeg
    - .png
    - .gif
    - .tiff
    - .ico
    - .svg
    - .eot
    - .otf
    - .ttf
    - .woff
    - .woff2

  extensions:
    - .jsx
    - .mjs
    - .js
    - .sass
    - .scss
    - .css
    - .module.sass
    - .module.scss
    - .module.css
    - .png
    - .svg
    - .gif
    - .jpeg
    - .jpg

development:
  <<: *default
  compile: true

  # Verifies that correct packages and versions are installed by inspecting package.json, yarn.lock, and node_modules
  check_yarn_integrity: true

  # Reference: https://webpack.js.org/configuration/dev-server/
  dev_server:
    https: false
    host: localhost
    port: 3035
    public: localhost:3035
    hmr: false
    # Inline should be set to true if using HMR
    inline: true
    overlay: true
    compress: true
    disable_host_check: true
    use_local_ip: false
    quiet: false
    pretty: false
    headers:
      "Access-Control-Allow-Origin": "*"
    watch_options:
      ignored: "**/node_modules/**"

test:
  <<: *default
  compile: true

  # Compile test packs to a separate directory
  public_output_path: packs-test

production:
  <<: *default

  # Production depends on precompilation of packs prior to booting for performance.
  compile: false

  # Extract and emit a css file
  extract_css: true

  # Cache manifest.json for performance
  cache_manifest: true

I can provide more details if needed, and I will update this issue should I find something.

Thanks!

[phacks]

Issue was that webpacker was listed under DevDependencies instead of Dependencies (see #117 and #1751). Second time this bit me, I need to write it down on a post-it note and forever display it on top of my monitor 😅