Puma crashing on new app

I just launched a new app on Render. It deploys successfully and puma starts up. But when I access the public URL, the page never loads, and I see this in the log over and over again.

Jul 16 01:57:41 PM  [888] ! Unable to start worker
Jul 16 01:57:41 PM  [888] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
Jul 16 01:57:41 PM  [888] Early termination of worker
Jul 16 01:57:44 PM  [892] ! Unable to start worker
Jul 16 01:57:44 PM  [892] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
Jul 16 01:57:44 PM  [892] Early termination of worker
Jul 16 01:57:46 PM  [894] ! Unable to start worker
Jul 16 01:57:46 PM  [894] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
Jul 16 01:57:46 PM  [894] Early termination of worker
Jul 16 01:58:02 PM  [898] ! Unable to start worker
Jul 16 01:58:02 PM  [898] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
Jul 16 01:58:02 PM  [898] Early termination of worker
Jul 16 01:58:03 PM  [901] ! Unable to start worker
Jul 16 01:58:04 PM  [901] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'
Jul 16 01:58:04 PM  [901] Early termination of worker
Jul 16 01:58:06 PM  [904] ! Unable to start worker
Jul 16 01:58:06 PM  [904] /opt/render/project/.gems/ruby/3.1.0/gems/zeitwerk-2.6.0/lib/zeitwerk/loader/callbacks.rb:25:in `on_file_autoloaded'

When I ssh and check the processes, the puma workers have been respawned with new process IDs. I’m not sure how to troubleshoot this because I don’t have access to any logs.

Update: Found a way to troubleshoot.

I discovered this command that I could run after SSHing in. It gave me the error I needed to fix:

rails zeitwerk:check --trace