Rails assets are loading veeeery slow (45s+) with zeus when config.assets.debug = true

[wojtha]

Description of Problem

After upgrade from El Capitan to macOS High Sierra (and enabling export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES) the rails server in development mode behaves differently. With config.assets.debug = true and two dozens of asset files, EVERY page load takes 45-60 secs CPU usage of zeus process is very high until all assets are rendered. I seems that assets are compiled again and again during each request. When I run the server without zeus it takes 2-3 secs. Setting config.assets.debug = false makes the page loading time to be sane again but it complicates the frontend development so it is not a long term solution.

System details

• macOS High Sierra - Darwin mephisto.local 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64 x86_64 with OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
• ruby 2.3.7
• zeus 0.15.4
• rails 4.1.16
• sprockets-rails 2.3.3
• sprockets 2.12.5

📄 zeus.json
📄 custom_plan.rb

Steps to Reproduce

# development.rb
config.cache_classes = false
config.eager_load = false
config.serve_static_assets = true
config.assets.debug = true

Observed Behavior

Loading assets with config.assets.debug = true is veeeery slow (45 sec and even more).

zeus start
zeus s

Expected Behavior

Loading assets with config.assets.debug = true is fast as via rails server (2-4 sec)

bundle exec rails s

Short term workaround

Set config.assets.debug = false and do not use zeus server for frontend assets development.

zeus start
zeus s