Bug #15720
Updated by chocolateboy (Chocolate Boy) over 6 years ago
```ruby 
 module M1 
   refine Kernel do 
     def foo 
       'foo called!' 
     end 
   end 
 end 
 module M2 
   refine Kernel do 
     def bar 
       'bar called!' 
     end 
   end 
 end 
 using M1 
 puts foo 
 puts bar 
 ``` 
 Expected: 
 ``` 
 foo called! 
 Traceback (most recent call last): 
 bug.rb:20:in `<main>': undefined local variable or method `bar' for main:Object (NameError) 
 ``` 
 Actual: 
 ``` 
 foo called! 
 Traceback (most recent call last): 
 bug.rb:20:in `<main>': stack level too deep (SystemStackError) 
 ``` 
 Platform: Linux (Arch) 
 ruby -v: Same result on: 
 - ruby 2.7.0dev (2019-03-21 trunk 67332) [x86_64-linux] 
 - ruby 2.6.2p47 (2019-03-13 revision 67232) [x86_64-linux] 
 - ruby 2.5.5p157 (2019-03-15 revision 67260) [x86_64-linux]