title: Rails 5 Heroku deploy error: ExecJS::ProgramError: SyntaxError: Unexpected token: name (autoRegisterNamespace)
body: <p>When trying to deploy a rails 5 app to heroku, I get the following error, when it reaches <code>Running: rake assets:precompile</code>:</p>
  
  <pre><code>remote:        ExecJS::ProgramError: SyntaxError: Unexpected token: name (autoRegisterNamespace) (line: 14767, col: 7, pos: 457487)
  remote:        Error
  remote:        at new JS_Parse_Error (&lt;eval&gt;:3623:11948)
  remote:        at js_error (&lt;eval&gt;:3623:12167)
  remote:        at croak (&lt;eval&gt;:3623:21858)
  remote:        at token_error (&lt;eval&gt;:3623:21995)
  remote:        at unexpected (&lt;eval&gt;:3623:22083)
  remote:        at semicolon (&lt;eval&gt;:3623:22601)
  remote:        at simple_statement (&lt;eval&gt;:3623:25779)
  remote:        at &lt;eval&gt;:3623:23567
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at block_ (&lt;eval&gt;:3623:27903)
  remote:        at &lt;eval&gt;:3623:23677
  remote:        at &lt;eval&gt;:3623:22774
  remote:        new JS_Parse_Error ((execjs):3623:11948)
  remote:        js_error ((execjs):3623:12167)
  remote:        croak ((execjs):3623:21858)
  remote:        token_error ((execjs):3623:21995)
  remote:        unexpected ((execjs):3623:22083)
  remote:        semicolon ((execjs):3623:22601)
  remote:        simple_statement ((execjs):3623:25779)
  remote:        (execjs):3623:23567
  remote:        (execjs):3623:22774
  remote:        block_ ((execjs):3623:27903)
  remote:        (execjs):3623:23677
  remote:        (execjs):3623:22774
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:47:in `rescue in block in call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:44:in `block in call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:75:in `block in lock'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `Locker'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `lock'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:43:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/uglifier-3.0.1/lib/uglifier.rb:179:in `run_uglifyjs'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/uglifier-3.0.1/lib/uglifier.rb:141:in `compile'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/uglifier_compressor.rb:52:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/uglifier_compressor.rb:28:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:75:in `call_processor'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:57:in `block in call_processors'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:56:in `reverse_each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:56:in `call_processors'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:134:in `load_from_unloaded'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:60:in `block in load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:317:in `fetch_asset_from_dependency_cache'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:44:in `load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:20:in `block in initialize'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:47:in `yield'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:47:in `load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/base.rb:66:in `find_asset'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/base.rb:73:in `find_all_linked_assets'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:142:in `block in find'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:114:in `block (2 levels) in logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:228:in `block in stat_tree'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:212:in `block in stat_directory'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:209:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:209:in `stat_directory'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:227:in `stat_tree'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:105:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:105:in `block in logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:104:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:104:in `logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:140:in `find'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:185:in `compile'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-3.1.1/lib/sprockets/rails/task.rb:68:in `block (3 levels) in define'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/rake/sprocketstask.rb:147:in `with_logger'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-3.1.1/lib/sprockets/rails/task.rb:67:in `block (2 levels) in define'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/rake-11.2.2/exe/rake:27:in `&lt;top (required)&gt;'
  remote:        V8::Error: SyntaxError: Unexpected token: name (autoRegisterNamespace)
  remote:        at js_error (&lt;eval&gt;:3623:12167)
  remote:        at croak (&lt;eval&gt;:3623:21858)
  remote:        at token_error (&lt;eval&gt;:3623:21995)
  remote:        at unexpected (&lt;eval&gt;:3623:22083)
  remote:        at semicolon (&lt;eval&gt;:3623:22601)
  remote:        at simple_statement (&lt;eval&gt;:3623:25779)
  remote:        at &lt;eval&gt;:3623:23567
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at block_ (&lt;eval&gt;:3623:27903)
  remote:        at &lt;eval&gt;:3623:23677
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at if_ (&lt;eval&gt;:3623:27671)
  remote:        at &lt;eval&gt;:3623:24326
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at block_ (&lt;eval&gt;:3623:27903)
  remote:        at ctor.body (&lt;eval&gt;:3623:27506)
  remote:        at function_ (&lt;eval&gt;:3623:27602)
  remote:        at expr_atom (&lt;eval&gt;:3623:30888)
  remote:        at maybe_unary (&lt;eval&gt;:3624:1562)
  remote:        at expr_ops (&lt;eval&gt;:3624:2333)
  remote:        at maybe_conditional (&lt;eval&gt;:3624:2425)
  remote:        at maybe_assign (&lt;eval&gt;:3624:2868)
  remote:        at expression (&lt;eval&gt;:3624:3194)
  remote:        at expr_atom (&lt;eval&gt;:3623:30640)
  remote:        at maybe_unary (&lt;eval&gt;:3624:1562)
  remote:        at expr_ops (&lt;eval&gt;:3624:2333)
  remote:        at maybe_conditional (&lt;eval&gt;:3624:2425)
  remote:        at maybe_assign (&lt;eval&gt;:3624:2868)
  remote:        at expression (&lt;eval&gt;:3624:3194)
  remote:        at simple_statement (&lt;eval&gt;:3623:25762)
  remote:        at &lt;eval&gt;:3623:23722
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at block_ (&lt;eval&gt;:3623:27903)
  remote:        at ctor.body (&lt;eval&gt;:3623:27506)
  remote:        at function_ (&lt;eval&gt;:3623:27602)
  remote:        at expr_atom (&lt;eval&gt;:3623:30888)
  remote:        at maybe_unary (&lt;eval&gt;:3624:1562)
  remote:        at expr_ops (&lt;eval&gt;:3624:2333)
  remote:        at maybe_conditional (&lt;eval&gt;:3624:2425)
  remote:        at maybe_assign (&lt;eval&gt;:3624:2868)
  remote:        at expression (&lt;eval&gt;:3624:3194)
  remote:        at expr_list (&lt;eval&gt;:3623:31368)
  remote:        at subscripts (&lt;eval&gt;:3624:1271)
  remote:        at expr_atom (&lt;eval&gt;:3623:30952)
  remote:        at maybe_unary (&lt;eval&gt;:3624:1562)
  remote:        at expr_ops (&lt;eval&gt;:3624:2333)
  remote:        at maybe_conditional (&lt;eval&gt;:3624:2425)
  remote:        at maybe_assign (&lt;eval&gt;:3624:2868)
  remote:        at expression (&lt;eval&gt;:3624:3194)
  remote:        at expr_atom (&lt;eval&gt;:3623:30640)
  remote:        at maybe_unary (&lt;eval&gt;:3624:1562)
  remote:        at expr_ops (&lt;eval&gt;:3624:2333)
  remote:        at maybe_conditional (&lt;eval&gt;:3624:2425)
  remote:        at maybe_assign (&lt;eval&gt;:3624:2868)
  remote:        at expression (&lt;eval&gt;:3624:3194)
  remote:        at simple_statement (&lt;eval&gt;:3623:25762)
  remote:        at &lt;eval&gt;:3623:23722
  remote:        at &lt;eval&gt;:3623:22774
  remote:        at &lt;eval&gt;:3624:3569
  remote:        at parse (&lt;eval&gt;:3624:3809)
  remote:        at parse (&lt;eval&gt;:3958:22)
  remote:        at uglifier (&lt;eval&gt;:4001:13)
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:45:in `block in call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:75:in `block in lock'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `Locker'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:73:in `lock'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/execjs-2.7.0/lib/execjs/ruby_racer_runtime.rb:43:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/uglifier-3.0.1/lib/uglifier.rb:179:in `run_uglifyjs'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/uglifier-3.0.1/lib/uglifier.rb:141:in `compile'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/uglifier_compressor.rb:52:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/uglifier_compressor.rb:28:in `call'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:75:in `call_processor'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:57:in `block in call_processors'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:56:in `reverse_each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/processor_utils.rb:56:in `call_processors'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:134:in `load_from_unloaded'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:60:in `block in load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:317:in `fetch_asset_from_dependency_cache'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/loader.rb:44:in `load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:20:in `block in initialize'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:47:in `yield'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/cached_environment.rb:47:in `load'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/base.rb:66:in `find_asset'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/base.rb:73:in `find_all_linked_assets'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:142:in `block in find'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:114:in `block (2 levels) in logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:228:in `block in stat_tree'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:212:in `block in stat_directory'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:209:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:209:in `stat_directory'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/path_utils.rb:227:in `stat_tree'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:105:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:105:in `block in logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:104:in `each'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/legacy.rb:104:in `logical_paths'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:140:in `find'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/sprockets/manifest.rb:185:in `compile'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-3.1.1/lib/sprockets/rails/task.rb:68:in `block (3 levels) in define'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-3.7.0/lib/rake/sprocketstask.rb:147:in `with_logger'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/sprockets-rails-3.1.1/lib/sprockets/rails/task.rb:67:in `block (2 levels) in define'
  remote:        /tmp/build_371be96e0ec063bb6c90d7770da64944/vendor/bundle/ruby/2.2.0/gems/rake-11.2.2/exe/rake:27:in `&lt;top (required)&gt;'
  remote:        Tasks: TOP =&gt; assets:precompile
  remote:        (See full trace by running task with --trace)
  </code></pre>
  
  <p>My Gemfile looks like this:</p>
  
  <pre><code>source 'https://rubygems.org'
  
  gem 'rails', '~&gt; 5.0.0'
  gem 'pg'
  gem 'puma', '~&gt; 3.0'
  gem 'httparty', '~&gt; 0.14.0'
  
  gem 'sass-rails', '~&gt; 5.0'
  gem 'uglifier', '&gt;= 1.3.0'
  gem 'coffee-rails', '~&gt; 4.2'
  gem 'jquery-rails', '~&gt; 4.1', '&gt;= 4.1.1'
  gem 'haml-rails', '~&gt; 0.9.0'
  gem 'bootstrap-sass', '~&gt; 3.3', '&gt;= 3.3.7'
  gem 'owlcarousel-rails', '~&gt; 1.1', '&gt;= 1.1.3.3'
  gem 'font-awesome-rails', '~&gt; 4.6', '&gt;= 4.6.3.1'
  
  
  gem 'turbolinks', '~&gt; 5'
  gem 'jbuilder', '~&gt; 2.5'
  # Use Redis adapter to run Action Cable in production
  # gem 'redis', '~&gt; 3.0'
  
  gem 'therubyracer'
  gem 'execjs'
  
  group :development, :test do
    gem 'byebug', platform: :mri
  end
  
  group :development do
    gem 'web-console'
    gem 'listen', '~&gt; 3.0.5'
    gem 'spring'
    gem 'spring-watcher-listen', '~&gt; 2.0.0'
  end
  
  gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
  </code></pre>
  
  <p>I tried both with and without:</p>
  
  <pre><code>gem 'therubyracer'
  gem 'execjs'
  </code></pre>
  
  <p>Nothing helps. Running rake assets:precompile locally on my mac works...</p>