How can I fix a Rails 5 precompile assets rb_sysopen error?

Question

I am trying to locally precompile assets (for production) and I get an error.

My steps:

1. bundle exec rake assets:clobber --trace (to remove public/assets so I perform a clean compile)
2. bundle exec rake assets:precompile RAILS_ENV=production --trace (to compile assets ready to upload to GitHub/Heroku)

I am using: Rails (5.2.2), Ruby (2.6.6), Bundler (2.4.4), Windows (10)

What happens A lot of my .js / .css / .jpg / .png files appear to precompile fine but then it always gives the error when it reaches this glyphicons-halflings-regular file. (Actually 24-hrs ago it tripped up on a .png file - I'm not sure what changed since then - I think I updated the bundler version and now it fails on a different file)

The error message:

Errno::ENOENT: No such file or directory @ rb_sysopen - C:/Users/..../...../public/assets/flatty/bootstrap/glyphicons-halflings-regular-5ff7c239555476e939e86d457bb78424b945b733b2c23791d9807c2357259d43.eot.103323240.10692.178366
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:278:in `initialize'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:278:in `open'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/sprockets-3.7.2/lib/sprockets/path_utils.rb:278:in `atomic_write'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/sprockets-3.7.2/lib/sprockets/asset.rb:165:in `write_to'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/sprockets-3.7.2/lib/sprockets/manifest.rb:210:in `block (2 levels) in compile'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/safe_task_executor.rb:24:in `block in execute'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:41:in `block in synchronize'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:41:in `synchronize'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/synchronization/mutex_lockable_object.rb:41:in `synchronize'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/safe_task_executor.rb:19:in `execute'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/ivar.rb:169:in `safe_execute'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/future.rb:55:in `block in execute'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:363:in `run_task'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:352:in `block (3 levels) in create_worker'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:335:in `loop'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:335:in `block (2 levels) in create_worker'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:334:in `catch'
C:/Ruby26-x64/lib/ruby/gems/2.6.0/gems/concurrent-ruby-1.1.8/lib/concurrent-ruby/concurrent/executor/ruby_thread_pool_executor.rb:334:in `block in create_worker'
Tasks: TOP => assets:precompile

Questions:

Any ideas? I know a lot of my gems are on old versions, but this precompile used to work for me and I do not know what has changed. Could it be because some gems or ruby or bundler or something are using older versions (but they used to work?)

Answer 1

After trying many different ideas from other threads (e.g. removing hyphens in file and folder names, removing '.' etc.) I discovered that the problem for me was the fact the local path to the file was too long.

If my path to the C:/Users//Documents/.../.../.../public/assets/.... .png was 240 characters it did not work. If the path was 216 characters the precompile worked fine.

So, simply by cloning the database into a local folder with a short filename reduced the lengths of these paths and the precompile worked.
Perhaps in the future I will need to shorten the folder names within my app, or reduce the depth of the path to the app on my hard drive.
Perhaps there is even a way of allowing long pathnames to files within an app but I could not find such a setting.