Rails console output doesn't show any results when called from Dokku

Question

Description of problem:
I moved from heroku to dokku. Really happy. Recently I tried to run rails console to make some operations with db. Apparently console starting but not showing any output of the result. My app started from rails v3, then upgraded to rails 5 and currently running rails 6.0 and ruby 2.6.5

Steps to Reproduce:
dokku run myapp rails c

Result:
Screenshot

Expected Result:
irb(main):001:0> 5 + 6
=> 11

Steps which I tried to resolve:

• Use pry instead of irb.
• Deploy to other cloud provider
  Both unsuccessful.

Then I tried to deploy newly created rails 6 app. And console works for it... So I want to hear any suggestions what options can be wrong in my app.

Related issue on stackoverflow:
Rails console hanging in dokku droplet

Answer 1

This was a bug in Dokku related to the interactive mode of 'dokku run' command. Recent version 0.19.8 fixing this problem. Console output is showing after upgrade to this versions of Dokku.