Defect #38155

Redmine 5: RuntimeError when reloading Rails console

Added by Thomas Löber 27 days ago. Updated 8 days ago.

Status:ConfirmedStart date:
Priority:NormalDue date:
Assignee:-% Done:


Target version:-
Resolution: Affected version:



When I start a Rails console in development and at some point run a reload! to reload changes I have just made to the source code, I get a RuntimeError:

> rails console
Loading development environment (Rails 6.1.7)
irb(main):001:0> reload!
Traceback (most recent call last):
        7: from config/initializers/30-redmine.rb:11:in `block in <top (required)>'
        6: from lib/redmine/preparation.rb:163:in `prepare'
        5: from lib/redmine/menu_manager.rb:251:in `map'
        4: from lib/redmine/preparation.rb:164:in `block in prepare'
        3: from lib/redmine/menu_manager.rb:321:in `push'
        2: from lib/redmine/menu_manager.rb:403:in `add'
        1: from lib/redmine/menu_manager.rb:386:in `add_at'
RuntimeError (Child already added)

The source of the error is Redmine::Preparation.prepare, which is called in this to_prepare block in config/initializers/30-redmine.rb:

Rails.application.config.to_prepare do
  I18n.backend =
  # Forces I18n to load available locales from the backend
  I18n.config.available_locales = nil


The reason for the error is that Rails.application.reloader.reload! correctly runs the prepare callbacks twice, but Redmine::Preparation.prepare does not support being called multiple times.


We already call prepare a thoroughly variable number of times -- if your prepare handler isn't idempotent, you're going to have a bad time.

So I changed the classes used in Redmine::Preparation to be idempotent. Please see the attached patch.

Now reloading works:

=> true

Best regards,

Make_Redmine_preparation_idempotent.patch Magnifier (2.78 KB) Thomas Löber, 2023-01-05 18:17

Make_Redmine_preparation_idempotent_v2.patch Magnifier (2.9 KB) Thomas Löber, 2023-01-24 14:21


#1 Updated by Go MAEDA 27 days ago

  • Tracker changed from Patch to Defect
  • Status changed from New to Confirmed

#2 Updated by Mischa The Evil 8 days ago

I've had a quick look at the attached patch file (didn't test it though). It seems to also change/break some features too, namely:
  • Feature #14008 (Add a warning if 2 plugins have the same settings partial name);
  • Protection against registering multiple wiki formatters with the same name.

This should be tested carefully before it is being committed.

#3 Updated by Thomas Löber 8 days ago

You are absolutely right. I have added an updated patch. (I am not allowed to delete the first patch, though.)

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