rails assets:precompile does not create /public/packs directory

[buhrmi]

Hello,

I have a pretty straight-forward rails app that I am deploying using dokku. In development it works fine, but in production I get the error

2018-10-18T07:05:37.632168000Z app[web.1]: [1d5a0a60-b707-41dd-a6d7-648e26e1db66] ActionView::Template::Error (Webpacker can't find app.js in /app/public/packs/manifest.json. Possible causes:
2018-10-18T07:05:37.632171108Z app[web.1]: 1. You want to set webpacker.yml value of compile to true for your environment
2018-10-18T07:05:37.632173344Z app[web.1]:    unless you are using the `webpack -w` or the webpack-dev-server.
2018-10-18T07:05:37.632186203Z app[web.1]: 2. webpack has not yet re-run to reflect updates.
2018-10-18T07:05:37.632188805Z app[web.1]: 3. You have misconfigured Webpacker's config/webpacker.yml file.
2018-10-18T07:05:37.632190932Z app[web.1]: 4. Your webpack configuration is not creating a manifest.
2018-10-18T07:05:37.632193095Z app[web.1]: Your manifest contains:
2018-10-18T07:05:37.632195113Z app[web.1]: {
2018-10-18T07:05:37.632197163Z app[web.1]: }
2018-10-18T07:05:37.632199464Z app[web.1]: ):

Here is my webpacker.yml

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

default: &default
  source_path: app/javascript
  source_entry_path: packs
  public_output_path: packs
  cache_path: tmp/cache/webpacker

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

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

  extensions:
    - .coffee
    - .vue
    - .js
    - .sass
    - .scss
    - .css
    - .module.sass
    - .module.scss
    - .module.css
    - .png
    - .svg
    - .gif
    - .jpeg
    - .jpg

development:
  <<: *default
  compile: true

  # Reference: https://webpack.js.org/configuration/dev-server/
  dev_server:
    https: false
    host: localhost
    port: 3035
    public: localhost:3035
    hmr: true
    # 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
    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

  # Cache manifest.json for performance
  cache_manifest: true

In the deployment logs I can see

       Webpacker is installed 🎉 🍰
       Using /tmp/build/config/webpacker.yml file for setting up webpack paths
       Compiling…
       Compiled all packs in /tmp/build/public/packs
       Asset precompilation completed (21.25s)
       Cleaning assets
       Running: rake assets:clean
-----> Detecting rails configuration

But when I ls /app/public, I only get

404.html  422.html  500.html  apple-touch-icon.png  apple-touch-icon-precomposed.png  assets  favicon.ico  robots.txt

Does anybody know what might be amiss?

[buhrmi]

Similarly,

if I dokku enter app, and compile manually, I get this

$ RAILS_ENV=production rake webpacker:compile
Webpacker is installed 🎉 🍰
Using /app/config/webpacker.yml file for setting up webpack paths
Compiling…
Compiled all packs in /app/public/packs
$ ls /app/public/packs
ls: cannot access '/app/public/packs': No such file or directory

Locally the packs compile just fine...

[buhrmi]

I was able to nail the issue down to some npm packages not being installed (probably a messed up yarn.lock file or something similar). Reinstalling all yarn packs locally and committing the lock file to the repo fixed the server-side building. Just in case somebody else has a similar issue.

[Kulgar]

For me it was some people who wrongly put some libs in dev dependencies...

So, assets were compiling fine in development, but not on staging. What is strange is that I got no errors (everything was like @buhrmi said).

Webpacker should complain about missing libraries when it tries to compile and fails to do so, shouldn't it?

[jakeNiemiec]

What is strange is that I got no errors (everything was like @buhrmi said)

@Kulgar Errors were suppressed to reduce dev server output in development. I feel like this will be a continual source of problems for new users. Here is the commit.

it was some people who wrongly put some libs in dev dependencies...

Discussed at length in this issue.

[mroliveira7]

I'm using it with docker and i had to manually run rake webpacker:compile on production and all worked fine. I think i'll put it in my dockerfile

[cazBlue]

@mroliveira7 Thanks for the note on Docker, that got it for me as well.

[ghost]

I have deployed the Rails App on AWS EC2 instance using Rails and Unicorn.
But rake webpacker:compile command not generating public/packs even public/assets is created.
I also tried rake assets:precompile RAILS_ENV=production but it was the same.
Anyone can help me?

[rossta]

@nikolacojcic99 Sounds like something might be failing.

Make sure your webpacker.yml ensures compilation logs are printed: webpack_compile_output: true

Inspect the logs at your next deploy to look for errors during the compilation process. From there, folks may be able to help diagnose the specific error.

[dfvasquez]

I have deployed the Rails App on AWS EC2 instance using Rails and Unicorn.
But rake webpacker:compile command not generating public/packs even public/assets is created.
I also tried rake assets:precompile RAILS_ENV=production but it was the same.
Anyone can help me?

Could you fix this? I'm having the same error :(

[Shalashtein]

Bumping I've got the same issue while deploying to AWS EB

[selcuktoklucu]

I've been trying to figure this issue for a long time, and still didn't get a solution yet. I'm working on Heroku, I get this error in these two different scenarios:
Upgrading yarn version to 2
Upgrading rails version to 6.1 from 6.0.3.x

In both of these I had to upgrade webpacker version from 4.2.2, to any version 5.x
I don't see any errors in Heroku deployment logs, but when I visit the main page, I got you mentioned above, basically empty manifest.json file.

I login to heroku bash, and tried to compile manually, and here is the result.

bundle exec rails webpacker:compile
..
..
..
Compiling...
Compiled all packs in /app/public/packs
$ ls /app/public/packs
ls: cannot access '/app/public/packs': No such file or directory

Ideally, after running this command, we should see a manifest.json file with some content and js directory which has several compiled css and js files in it.
In some cases, this can be in <project>/public/packs path, but it not there either.

So it doesn't throw any error, but it also doesn't compile. I also tried rails assets:precompile the result is the same.

[samahmadsam]

bundle exec rails webpacker:compile

when i run this command so got a error webpack not found any suggestion plz why this error is coming

[James-Wilkinson-git]

Also having the same problem on webpacker 5 ran rake assets preconoile on heroku and got a notice that Webpack-cli wasn’t there so trying to move it to dependency instead if dev dependency.