Heroku push - ExecJS::RuntimeError: SyntaxError: Name expected

Question

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 [email protected]: The platform "linux" is incompatible with this module.
remote:        info "[email protected]" 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)

Answer 1

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

Answer 2

I believe the problem is connected with the yarn installation on your linux server

In fact you can find that file in yarn github repository

Yarn fsevents-1.1.2

also you can find similar issues where the heroku installation of yarn would fail with the same error warning [email protected]: The platform "linux" is incompatible with this module.

The error is the same warning [email protected]: The platform "linux" is incompatible with this module. info "[email protected]" is an optional dependency and failed compatibility check. Excluding it from installation.

Heroku fails to install yarn on linux platform

Yarn was added in Rails 5.1 and I had to troubleshoot this error too and I also opened an issue on SO.

My problem was in development, because I have Linux Mint. Probably installing yarn in development allowed me to not experience the problem in production.

Still I had problems installing it in development with node.js so I ended up using npm command npm install yarn -g and you can run this on your heroku server with heroku run npm install yarn -g or you can use nodejs, the guide for the yarn installation are hear

https://yarnpkg.com/en/docs/install

also this is a query of a list of issues that are very similar, you can read those post and probably find the solution to your problem. This issue are not from ruby on rails, but other frameworks that use nodejs.

In this case you are installing also yarn with nodejs, so maybe the problem is connected with nodejs

https://duckduckgo.com/?q=heroku+yarn+installation+The+platform+%22linux%22+is+incompatible&atb=v52-6_b&ia=qa

Explanation of FSEvents API

This appears to be a dependency problem with fsevents. Your OS, Arch Linux, doesn't support it. If you head over to Strongloop's fsevents Github page, you'll see this in their README

Native access to OS X FSEvents in Node.js The FSEvents API in OS X allows applications to register for notifications of changes to a given directory tree. It is a very fast and lightweight alternative to kqueue. So, I would say this isn't a Yarn issue. The other errors are probably a result of the previous failing.

Read more at

https://github.com/yarnpkg/yarn/issues/2142

Anyway they should have solved this with this fix

https://github.com/yarnpkg/yarn/pull/2279

maybe you can open an issue if you can not solve this