webpacker: Command "webpack" not found.

I’m deploying an upgraded Rails 4.x -> 5.1 app to Heroku and am getting the error

Command "webpack" not found.

I’ve gone on to the dyno directly and attempted to run rake assets:precompile which fails with the message:

Webpacker is installed 🎉 🍰
Using /app/config/webpacker.yml file for setting up webpack paths
[Webpacker] Compiling assets 🎉
[Webpacker] Compilation Failed
yarn run v0.22.0
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

error Command "webpack" not found.

This seems to be coming from https://github.com/rails/webpacker/blob/f35331c678c7fd44ef225553629ee3e14989030e/lib/tasks/webpacker/compile.rake#L13

Am I correct in understanding that executing rake assets:precompile is all that needs to occur for a deployment? ie, that handles installing the yarn dependencies etc?

I found that if I do yarn install first and then assets:precompile it works - but I didn’t think I had to do that.

~ $ rake webpacker:verify_install
Webpacker is installed 🎉 🍰
Using /app/config/webpacker.yml file for setting up webpack paths

About this issue

  • Original URL
  • State: closed
  • Created 7 years ago
  • Reactions: 18
  • Comments: 30 (20 by maintainers)

Commits related to this issue

Most upvoted comments

For anyone updating from Rails 4.x to 5.1.x to add yarn binstub -

bundle config --delete bin
# Will create yarn binstub
rails app:update:bin
git add bin
+13
gauravtiwari on Jun 21, 2017

@jnfeinstein Just install webpacker, bundle exec rails webpacker:install. Also you would need to remove ./bin folder from .gitignore

+11
gauravtiwari on Sep 12, 2017

thank you @jakeNiemiec , bundle exec rails webpacker:install adds it to dependencies but I will edit and clearify my comment.

+5
mtoygar on Jun 20, 2019

In my case rails webpacker:install was silently ‘failing’. When I check node_modules/.bin folder there was no webpack file and this results in the Command "webpack" not found. error. (webpack source code reference)

After some investigation, I manually tried to add webpack using ~yarn add --dev webpack webpack-dev-server~yarn add webpack webpack-dev-server command and saw the below error(webpack module cant be installed because of some DNS related problem).

error An unexpected error occurred: "https://registry.npmjs.org/webpack: Hostname/IP does not match certificate's altnames: Host: registry.npmjs.org. is not in the cert's altnames: DNS:a.sni.fastly.net, DNS:a.sni.global-ssl.fastly.net".

After some research, the above problem is solved with the command below.

dig https://registry.npmjs.org/webpack @1.1.1.1

Then, I remove node_modules, and generate it once more using bundle exec rails webpacker:install. This time I’ve had node_modules/.bin/webpack file and the error was fixed.

+5
mtoygar on Jun 20, 2019

when error happens with capistrano:

before "deploy:assets:precompile", "deploy:yarn_install"

namespace :deploy do
  desc 'Run rake yarn:install'
  task :yarn_install do
    on roles(:web) do
      within release_path do
        execute("cd #{release_path} && yarn install")
      end
    end
  end
end
+3
dorianmariefr on Oct 17, 2020

@ytbryan the buildpack maintainer here. You do not need to use the Node buildpack.

+3
schneems on Jun 20, 2017

Looks like it’s only gets generated with rails new (5.1+) - https://github.com/rails/rails/blob/801b33a4812c937a7e726d4060e2e3e9361c56fa/railties/lib/rails/generators/rails/app/templates/bin/yarn

+2
gauravtiwari on Jun 20, 2017

Seems like the task is invoked but there is no yarn binstub present since you were using Rails 4.

screen shot 2017-06-20 at 20 33 27

Please regenerate them - bundle install --binstubs

+2
gauravtiwari on Jun 20, 2017

You need run task yarn install before assets:precompile.

Look at documentation

https://github.com/rails/webpacker/blob/master/docs/deployment.md

+1
selivandex on Jun 21, 2019
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