TypeError: no implicit conversion of nil into String

[andreistangacianu]

So - after adding all the requires and running rake assets:precompile I'm getting this error:

TypeError: no implicit conversion of nil into String
(in /Users/andrei/.rvm/gems/ruby-2.1.1/gems/polymer-paper-rails-0.2.5/app/assets/components/core-dropdown/metadata.html)

I'm using ruby 2.1.1p76 on rails 4.0.8.
Do you have any idea what might have gone wrong here ?

[jambyung]

I'm having exactly same issue. running rake assets:precompile gives me exactly same error.
Ruby 2.2.0 Rails 4.2
TypeError: no implicit conversion of nil into String
(in /Users/me/.rvm/gems/ruby-2.1.5/gems/polymer-paper-rails-0.2.5/app/assets/components/core-dropdown/metadata.html)

/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:80:in initialize' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:80:innew'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:80:in resolve' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:146:inrequire_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/polymer-rails-0.2.6/lib/polymer-rails/processors/components_processor.rb:23:in block in require_imports' /Users/me/.rvm/gems/ruby-2.1.5/gems/nokogiri-1.6.5/lib/nokogiri/xml/node_set.rb:237:inblock in each'
/Users/me/.rvm/gems/ruby-2.1.5/gems/nokogiri-1.6.5/lib/nokogiri/xml/node_set.rb:236:in upto' /Users/me/.rvm/gems/ruby-2.1.5/gems/nokogiri-1.6.5/lib/nokogiri/xml/node_set.rb:236:ineach'
/Users/me/.rvm/gems/ruby-2.1.5/gems/polymer-rails-0.2.6/lib/polymer-rails/processors/components_processor.rb:22:in require_imports' /Users/me/.rvm/gems/ruby-2.1.5/gems/polymer-rails-0.2.6/lib/polymer-rails/processors/components_processor.rb:15:inprocess'
/Users/me/.rvm/gems/ruby-2.1.5/gems/polymer-rails-0.2.6/lib/polymer-rails/railtie.rb:18:in block (2 levels) in <class:Railtie>' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/processor.rb:29:incall'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/processor.rb:29:in evaluate' /Users/me/.rvm/gems/ruby-2.1.5/gems/tilt-1.4.1/lib/tilt/template.rb:103:inrender'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:197:in block in evaluate' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:194:ineach'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/context.rb:194:in evaluate' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/processed_asset.rb:12:ininitialize'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:374:in new' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:374:inblock in build_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:395:in circular_call_protection' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:373:inbuild_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:94:in block in build_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/caching.rb:58:incache_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:93:in build_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:287:infind_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:61:in find_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/bundled_asset.rb:16:ininitialize'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:377:in new' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:377:inbuild_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:94:in block in build_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/caching.rb:58:incache_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:93:in build_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/base.rb:287:infind_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/index.rb:61:in find_asset' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:211:inblock in find_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:257:in benchmark' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:210:infind_asset'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:119:in block in compile' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:118:ineach'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/sprockets/manifest.rb:118:in compile' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.4/lib/sprockets/rails/task.rb:70:inblock (3 levels) in define'
/Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-2.12.3/lib/rake/sprocketstask.rb:146:in with_logger' /Users/me/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.4/lib/sprockets/rails/task.rb:69:inblock (2 levels) in define'
/Users/me/.rvm/gems/ruby-2.1.5/bin/ruby_executable_hooks:15:in eval' /Users/me/.rvm/gems/ruby-2.1.5/bin/ruby_executable_hooks:15:in

'
Tasks: TOP => assets:precompile

[ephraimrothschild]

Same thing here
Ruby 2.1.5 on windows
rails 4.2.0

DL is deprecated, please use Fiddle
DL is deprecated, please use Fiddle
element template: validity error : ID imports already defined
rake aborted!
TypeError: no implicit conversion of nil into String
  (in C:/Ruby21-x64/lib/ruby/gems/2.1.0/gems/polymer-paper-rails-0.2.5/app/assets/components/core-dropdown/metadata.html)

Tasks: TOP => assets:precompile
(See full trace by running task with --trace)

[jasonwill]

I've patched both core and paper to play nicely with the asset pipeline. Tested with Ruby 2.1.5/Rails 4.2.0 on Yosemite and Ubuntu 14.04. Will submit a pull request but feel free to use these if you're in a pinch:

https://github.com/jasonwill/polymer-core-rails.git
https://github.com/jasonwill/polymer-paper-rails.git

[tddrmllr]

@jasonwill those forks fixed it for me. thanks!

[shawntoffel]

@jasonwill Are you still planning to submit a pull request?

[shawntoffel]

The metadata file causing the issue has been removed in version 0.5.5. See googlearchive/core-dropdown#8. I am currently working on a version bump to paper-elements 0.5.5.