Passenger can't start Rails 5 app with Forest Admin

Expected behavior

Start Rails 5 application.

Actual behavior

Passenger does not boot Rails 5 app.

Failure Logs

[ E 2020-12-29 00:42:39.0632 21407/T1c age/Cor/App/Implementation.cpp:305 ]: Could not spawn process for application /var/www/app/current: An error occurred while starting up the preloader. It sent an unknown response type "socket: unix:/tmp/passenger.G06gso5/apps.s/preloader.1bwmyct\n". Error ID: a1fe365c Error details saved to: /tmp/passenger-error-xm0eQ3.html Message from application: An error occurred while starting up the preloader. It sent an unknown response type &quot;socket: unix:/tmp/passenger.G06gso5/apps.s/preloader.1bwmyct\n&quot;.<br> Raw process output: ... [ E 2020-12-29 00:42:39.1126 21407/Tf age/Cor/Con/CheckoutSession.cpp:285 ]: [Client 5-2] Cannot checkout session because a spawning error occurred. The identifier of the error is a1fe365c. Please see earlier logs for details about the error. client_loop: send disconnect: Broken pipe

Context

  • Phusion Passenger: 5.0.29
  • Package Version: forest_liana gem -> 4
  • Rails Version: 5.2.2
  • Database Dialect: -
  • Database Version:

What it is interesting everything worked fine till yesterday. After removing Forest Liana from Gemfile (and initializers) Passenger correctly boots my Rails app. No new code was released neither DevOps work on server made. It’s sudden issue.

Hi @Lukasz,

As you also created a GitHub issue, let’s continue the discussion here: