Stack level too deep

[fynsta]

I installed Rails 6.1 today, but I got the error "Stack level too deep" with the following stack trace

        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `each'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:57:in `as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:174:in `block in as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `each'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:57:in `as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:174:in `block in as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `each'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:173:in `as_json'
        - activesupport (6.1.0) lib/active_support/core_ext/object/json.rb:57:in `as_json'

and so forth. This looks like a rails issue to me because it seems like some kind of recursive call stack.

System configuration

Rails version:
Rails 6.1.0

Ruby version:
ruby 2.6.1p33 (2019-01-30 revision 66950) [x86_64-darwin19]

[composerinteralia]

Could you provide a reproduction script or a sample application to reproduce the bug?

One way you might run into this error is if you try to turn an object that references itself into json:

x = {}
x[:x] = x
x.to_json

That would not be a Rails bug, but I think it would produce a stack trace like the one you show here.

[fynsta]

I see, thanks for the feedback!
I'll try to find the root of the problem. Is this something that might not have occurred in 6.0?

[MatheusSilvaSouza]

I also have that problem on Rails 5.2.4.4
It seems to be caused by a recursive call to as_json in activesupport-5.2.4.4/lib/active_support/core_ext/object/json.rb:174

[paulwis]

In my case, removing the meta_request gem solved this in 6.1.

[jeffblake]

In my case I was using a custom Logger formatter that called to_json at the end. Changed it to JSON.dump(hash) to fix it

[fynsta]

In my case, removing the meta_request gem solved this in 6.1.

That actually seems to have done the trick in my case. Thanks!

Closing the issue as it does not seem to be Rails' fault.

[zzemla]

For anyone looking for a solution:
dejan/rails_panel#177 (comment)

[leompeters]

Thank you, @zzemla. You rock!