I am encountering the following error when pushing to Heroku. Was working fine the other day. No major configuration changes on the commit I'm trying to push. I'm stumped at how to troubleshoot this. The Rails 5.1 application uses the following buildpacks:
1. heroku/nodejs
2. heroku/ruby
I'm making use of webpacker and yarn. I think that has something to do with it but having trouble digging for more information.
remote: -----> Preparing app for Rails asset pipeline
remote: Running: rake assets:precompile
remote: yarn install v0.27.5
remote: [1/4] Resolving packages...
remote: [2/4] Fetching packages...
remote: warning fsevents@1.1.2: The platform "linux" is incompatible with this module.
remote: info "fsevents@1.1.2" is an optional dependency and failed compatibility check. Excluding it from installation.
remote: [3/4] Linking dependencies...
remote: [4/4] Building fresh packages...
remote: Done in 6.62s.
remote: rake aborted!
remote: ExecJS::RuntimeError: SyntaxError: Name expected
remote: JS_Parse_Error.get ((execjs):3538:621)
remote: (execjs):4060:47
remote: (execjs):1:102
remote: Object.<anonymous> ((execjs):1:120)
remote: Module._compile (module.js:571:32)
remote: Object.Module._extensions..js (module.js:580:10)
remote: Module.load (module.js:488:32)
remote: tryModuleLoad (module.js:447:12)
remote: Function.Module._load (module.js:439:3)
remote: Module.runMain (module.js:605:10)
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:39:in `exec'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:21:in `eval'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/execjs-2.7.0/lib/execjs/external_runtime.rb:46:in `call'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/uglifier-3.2.0/lib/uglifier.rb:195:in `run_uglifyjs'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/uglifier-3.2.0/lib/uglifier.rb:157:in `compile'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/uglifier_compressor.rb:53:in `call'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/uglifier_compressor.rb:28:in `call'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:75:in `call_processor'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:57:in `block in call_processors'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in `reverse_each'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/processor_utils.rb:56:in `call_processors'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/loader.rb:134:in `load_from_unloaded'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/loader.rb:60:in `block in load'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/loader.rb:317:in `fetch_asset_from_dependency_cache'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/loader.rb:44:in `load'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:20:in `block in initialize'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/cached_environment.rb:47:in `load'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/base.rb:66:in `find_asset'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/base.rb:73:in `find_all_linked_assets'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:142:in `block in find'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:114:in `block (2 levels) in logical_paths'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:228:in `block in stat_tree'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:212:in `block in stat_directory'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:209:in `each'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:209:in `stat_directory'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/path_utils.rb:227:in `stat_tree'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:105:in `each'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:105:in `block in logical_paths'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:104:in `each'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/legacy.rb:104:in `logical_paths'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:140:in `find'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/sprockets/manifest.rb:185:in `compile'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-rails-3.2.0/lib/sprockets/rails/task.rb:68:in `block (3 levels) in define'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-3.7.1/lib/rake/sprocketstask.rb:147:in `with_logger'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/sprockets-rails-3.2.0/lib/sprockets/rails/task.rb:67:in `block (2 levels) in define'
remote: /tmp/build_d7b1075d17c0c421422ebdbfc017919a/vendor/bundle/ruby/2.4.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
remote: Tasks: TOP => assets:precompile
remote: (See full trace by running task with --trace)
remote: !
remote: ! Precompiling assets failed.
remote: !
remote: ! Push rejected, failed to compile Ruby app.
remote:
remote: ! Push failed
remote: Verifying deploy...
remote:
remote: ! Push rejected ....
Upon further research, discovered the problem to be related to Uglifier. When I copy and paste the contents of third party library datepicker.js into Uglifier I get the same error:
> Uglifier.compile( <<< file contents >>> )
ExecJS::RuntimeError: SyntaxError: Name expected
from JS_Parse_Error.get ((execjs):3538:621)
I discovered that the cause of this issue is related to a possible bug in Uglifier when it tries to process a third party library named js-datepicker (datepicker.js). I opened up an issue on the Uglifier Github: https://github.com/lautis/uglifier/issues/124
I figured out a workaround for this by including the minified js-datepicker in my app/assets/javascripts/application.js file like this.
//= require js-datepicker/datepicker.min