The asset "favicon/site.webmanifest" is not present in the asset pipeline.

[vkononov]

I know this issue has been addressed before by adding web_app_manifest.rb in initializers, but the same problem happens again when using sprockets -v 4.0.0.

The current workaround is to include gem 'sprockets', '< 4.0.0' inside `Gemfile.

[loust333]

I have the same problem.

[loust333]

Hi @vkononov,

I solved the problem by updating the

app/assets/config/manifest.js

Like this:

//= link_tree ../images

//= link favicon/site.webmanifest

//= link favicon/browserconfig.xml

and by updating the

config/initializers/web_app_manifest.rb

Like this:

Rails.application.config.assets.configure do |env|
  env.register_mime_type('application/manifest+json', extensions: ['.webmanifest', '.webmanifest.erb'])
end

Sprockets 4.0.0, checks the manifest.js to verify what needs to be loaded in the asset pipeline and we need to specify the erb file as indicated in the following quote:

Sprockets 4 will not chain asset extensions so .coffee.erb is explicitly registered in addition to .coffee. If your application introduces a new mime/extension combo it will be responsible for registering all combinations.

Source: https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#registering-all-versions-of-sprockets-in-processors

I hope it solved the problem for everyone.

[cirdes]

@loust333 thanks! Worked.

[minifast-winston]

Having a similar problem as #35 (comment). After making the same changes, we no longer got an error, and things seemed to link up correctly, however the file is not being processed as erb, so the resulting asset has the ruby call to asset_path instead of the expected return value.

Took a quick shot at adding an explicit transformer, but haven't had any luck yet. This was working fine in rails 5 for us, but we're attempting to upgrade to Rails 6 and this is one of the few outstanding issues remaining.

[minifast-winston]

@loust333 Did you add gem 'sprockets', '< 4.0.0' to your Gemfile as well or do anything additional? Thanks! :)

[loust333]

Hi @minifast-winston,

If you set gem 'sprockets', '< 4.0.0', you don't need to do the changes that I recommended.
It is only needed if the sprockets version is 4 or above -> gem 'sprockets', '>= 4.0.0'

:)

[minifast-winston]

@loust333 That's what I thought, just wanted to verify. I have everything in place, it's just not interpreting the webmanifest as .erb, so the asset path isn't evalutated. Guess I'll need to dig deeper into Sprockets.

[minifast-winston]

My hunch about needed to re-add the ERB Preprocessor seems to be correct. Looking over this pull request (#38), the line to re-add the ERB Preprocessor was exactly what was needed.

@loust333 Did you verify that the site.webmanifest was getting run through the the erb preprocessor? In my case, your work stopped my app from erroring, but had a broken asset path in the site.webmanifest itself.

[loust333]

@minifast-winston I didn't verify.

Thank you for the feedback. It wasn't being preprocessed.

I added the Sprockets::ERBProcessor as indicated in the issue (#38). It solved the problem. 😄

if(Sprockets::VERSION.split('.')[0].to_i >= 4)
    env.register_mime_type('application/manifest+json', extensions: ['.webmanifest', '.webmanifest.erb'])
    env.register_preprocessor('application/manifest+json', Sprockets::ERBProcessor)
  else
    env.register_mime_type('application/manifest+json', extensions: ['.webmanifest'])
  end 

Just tagging @cirdes and @vkononov. I think they had the same issue.

[maia]

@loust333 This solves the issue, thanks. If anyone has similar issues, I had to do the same for <meta name="msapplication-config" content="<%= asset_path 'favicon/browserconfig.xml' %>">:

env.register_mime_type('application/xml', extensions: ['.xml', '.xml.erb'])
env.register_preprocessor('application/xml', Sprockets::ERBProcessor)

…to ensure the generated filename is /assets/favicon/browserconfig-087d…3a9a.xml and does not have .erb as suffix.

[JuPlutonic]

Please like the comment if code in config/initializers/web_app_manifest.rb needs to be refactored (using Maia's #35 (comment)) with PR.

[shamas-]

@loust333 This solves the issue, thanks. If anyone has similar issues, I had to do the same for <meta name="msapplication-config" content="<%= asset_path 'favicon/browserconfig.xml' %>">:

env.register_mime_type('application/xml', extensions: ['.xml', '.xml.erb'])
env.register_preprocessor('application/xml', Sprockets::ERBProcessor)

…to ensure the generated filename is /assets/favicon/browserconfig-087d…3a9a.xml and does not have .erb as suffix.

If you're still getting the error after using this suggestion, take this post's advice: https://stackoverflow.com/a/60884374