Development server hangs on code changes

rubyonrails-talk
1

Hello all,

My colleagues and I are having issues with our development server hanging on code changes. There aren’t any traceback or errors on why this is happening, but I suspect it is ActionDispatch::Reloader causing the issue.

In config/environments/development.rb, I add this to see if ActionDispatch::Reloader could be causing the issue:

class WhatTheHeckMiddleware def initialize(app, opts = {}) @app = app @idx = opts[:idx] end

 # Just log when this middleware starts and ends
 def call(env)
   puts "~~ wth START #{@idx} ~~"
   res = @app.call(env)
   puts "~~ wth END #{@idx} ~~"
   res
 end

end

config.middleware.insert_before(ActionDispatch::Reloader, WhatTheHeckMiddleware, { idx: 1 }) config.middleware.insert_after(ActionDispatch::Reloader, WhatTheHeckMiddleware, { idx: 2 })

``

I reproduce the issue by making a code change and then server hangs:

2018-03-22T18:55:57 [I|app|] Started GET “/notification_recipients” for 127.0.0.1 at 2018-03-22 18:55:57 +0000 ~~ wth START 1 ~~ (server hangs here, no END statement is printed)

``

There is a similar issue found in graphql-ruby that did result in a commit to rails. (Their issue is where I got the debugging idea above) I tried the patch to rails without luck, It looks like we don’t even use the ActiveSupport::Reloader middleware mentioned in the issue.

We are using Rails 5.1.4

My questions are:

  • Does anyone have any ideas on what could be going on?

  • Am I correct in thinking something is going wrong in ActionDispatch::Reloader?

  • How can I debug this further?

Let me know if I can provide any more information.

Thanks!

2

Is the code you're changing related to the request method above? Does it work as expected when you make the change and restart the server?

Can you create and publish a simplified reproducible test case if this isn't open source?

If not, I'd say you just need to start adding debug logger statements (or pry breakpoints) to see where it stops...