How to build task 'assets:precompile'

Question

I'm getting that error on my production server, and can't figure out why. It happens when running this command:

bundle exec rake assets:precompile RAILS_ENV=production

I'm using Rails 3.1.0.rc6

It means there is no task `assets:precompile` for your application. May be a missing gem or something. — rubish, Aug 26 '11 at 14:21
which gem would that be? I had just run "gem install rails --pre" and then "rails new ..." — tybro0103, Aug 26 '11 at 14:48
Are you actually using bundler in production? Is your production server on Heroku? — Jack Chu, Aug 27 '11 at 11:00
@Jack Chu I'm just trying to compile the assets. No, not heroku. — tybro0103, Aug 29 '11 at 17:39
Are you sure you have sprockets installed? Also, you dont need RAILS_ENV=production, that specific task is always run as production by default. — Jack Chu, Aug 30 '11 at 02:22
In my case I just had to add the gem 'sass-rails' in the gemfile. Maybe it can help someone. — Alessandro De Simone, Mar 08 '15 at 10:33

Koraktor · Accepted Answer · 2011-11-08T08:44:27.290

84

This is most likely due your config/application.rb not requiring rails/all (the default), but some custom requires.

To resolve this, add the following to config/application.rb:

require 'sprockets/railtie'

edited Nov 08 '11 at 08:44

answered Aug 31 '11 at 19:11

Koraktor

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This is common issue for Mongoid users that delete rails/all config – Alexey Zakharov Sep 13 '11 at 05:40
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thank god, someone spotted this, I confirm the said phenomenon – Nik So Sep 15 '11 at 03:49
bingo. I am indeed a Mongoid user. – tybro0103 Sep 27 '11 at 21:08
So .. I have this problem, but this wasn't the problem. requiring sprockets/railtie was not missing from my config. – John Hinnegan Nov 15 '11 at 03:00
That problem was solved but I got a new error in terminal as: Sprockets::ArgumentError: manifest requires output filename – Atchyut Nagabhairava Sep 21 '16 at 07:03
Note that creating a Rails 5 API-only project with ```$ rails new my_api --api``` generates an application.rb file with that specific line commented out. – Pimentoso Oct 27 '16 at 16:26

score 8 · Answer 2 · answered Jul 24 '18 at 13:39

8

I was running this command -- out of sheer habit -- in the root of an API-only app, which, of course, has no assets.

answered Jul 24 '18 at 13:39

Niek

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Oh. thank you this saved me. My app was also an API-only application. – Promise Preston Mar 22 '20 at 15:50
Add me to the list.. – typicalk Jul 08 '22 at 13:57

score 5 · Answer 3 · answered Aug 07 '12 at 14:52

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I know this is an old post but I thought it might help someone (probably my future self) if I added this to the answers.

add to Capfile (or deploy.rb)

load 'deploy/assets'

add this to application.rb

require 'sprockets/railtie'

answered Aug 07 '12 at 14:52

engineerDave

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I'm having the same issue. but on rails 2. i've added these lines but it didn't help (and not to application.rb but to enviroment.rb) – Elmor Dec 08 '12 at 12:25
This fixed it for me on Thin + Rails 3.2 with Mongodb. Thanks!! – Nick Ryberg Jan 24 '14 at 20:41

score 3 · Answer 4 · answered Sep 02 '11 at 08:25

3

I think that it might be because you aren't requiring the asset gems in production. By default rails expects that you are pre-compiling your assets in production. Change this in config/application.rb:

Comment out this line:

Bundler.require *Rails.groups(:assets => %w(development test))

And uncomment this line:

Bundler.require(:default, :assets, Rails.env)

answered Sep 02 '11 at 08:25

Daniel Hoey

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I'm not a mongoid user like the currently accepted answer mentions in the comments. In my case I had a seperate environment just to precompile assets and the error went away once I added the new environment to the list mentioned in this answer. – ErJab Aug 08 '13 at 04:31
I had an extremely old app (2008), that doesn't even have sprockets, so this is the answer I needed. Cap defaults to expecting to precompile the asset pipeline, but since there is no asset pipeline it fails. – Josh from Qaribou Oct 20 '16 at 13:05

score 1 · Answer 5 · answered Aug 30 '11 at 01:34

That's strange. You could always try adding

load "sprockets/assets.rake"

to your Rakefile. It should be included by the actionpack railtie.

My Rakefile contains:

require File.expand_path('../config/application', __FILE__)
Qnm::Application.load_tasks

score 0 · Answer 6 · answered Jan 05 '23 at 05:10

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This worked for me.
Add require "sprockets/railtie" in applications.rb.
And create an empty manifest file app/assets/config/manifest.js

answered Jan 05 '23 at 05:10

wandji

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How to build task 'assets:precompile'

6 Answers6

add to Capfile (or deploy.rb)

add this to application.rb

Linked