NoMethodError: undefined method `key?' for #<Array:0x007fdbee0dfbc0>

[dankimio]

Expected behavior

Successful asset compilation.

Actual behavior

Exits with NoMethodError: undefined method 'key?' for #<Array:0x007fdbee0dfbc0> when running $ rake assets:precompile and using ES6.

System configuration

• Sprockets version: master at c5ae761027bc8f34f631b5943838af97aaacc657
• Ruby version: 2.4.1

Example App

Gemfile:

ruby '~> 2.4.1'

gem 'rails', '~> 4.2.9'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'sprockets', git: 'https://github.com/rails/sprockets.git'
gem 'babel-transpiler', '~> 0.7'

gem 'rails_admin', '~> 1.0'

manifest.js:

//= link_tree ../images
//= link_directory ../javascripts .js
//= link_directory ../stylesheets .css

.js.es6 extension is used for JavaScript assets.

Stack trace

rake aborted!
NoMethodError: undefined method `key?' for #<Array:0x007fdbee0dfbc0>
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/source_map_utils.rb:127:in `make_index_map'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/source_map_utils.rb:75:in `concat_source_maps'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:95:in `block (2 levels) in process_bundle_reducers'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:91:in `each'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:91:in `block in process_bundle_reducers'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:90:in `each'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:90:in `reduce'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:90:in `process_bundle_reducers'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/bundle.rb:53:in `call'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/processor_utils.rb:84:in `call_processor'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/processor_utils.rb:66:in `block in call_processors'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/processor_utils.rb:65:in `reverse_each'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/processor_utils.rb:65:in `call_processors'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/loader.rb:144:in `load_from_unloaded'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/loader.rb:59:in `block in load'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/loader.rb:318:in `fetch_asset_from_dependency_cache'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/loader.rb:43:in `load'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/cached_environment.rb:44:in `load'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/base.rb:69:in `find_asset'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/base.rb:76:in `find_all_linked_assets'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/bundler/gems/sprockets-c5ae761027bc/lib/sprockets/manifest.rb:125:in `block (2 levels) in find'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/safe_task_executor.rb:24:in `block in execute'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/synchronization/mri_lockable_object.rb:38:in `block in synchronize'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/synchronization/mri_lockable_object.rb:38:in `synchronize'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/synchronization/mri_lockable_object.rb:38:in `synchronize'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/safe_task_executor.rb:19:in `execute'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/promise.rb:531:in `block in realize'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:348:in `run_task'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:337:in `block (3 levels) in create_worker'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:320:in `loop'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:320:in `block (2 levels) in create_worker'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:319:in `catch'
/Users/dan/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/concurrent-ruby-1.0.5/lib/concurrent/executor/ruby_thread_pool_executor.rb:319:in `block in create_worker'
Tasks: TOP => assets:precompile

[pabse]

I have the same problem after upgrading to 4.0.0.beta5.

Reverting back to 4.0.0.beta4 fixed it for me.

[y-yagi]

I have the same problem. Probably caused by #402.
SourceMapUtils#concat_source_maps expects source map hash.
However, it seems there are cases where encode is not done and passed in array of source mapping hashes.

[schneems]

I've gotten around this by clearing my cache and trying again. Can someone confirm that the above script reproduces the issue? If I can repro the problem I can work on it.

[schneems]

Going to close this. If someone else can reproduce, please let me know I can re-open.