Hello again,

over the weekend, I have made a modified version of the debug.rb file
to also handle the "raise" event (from eval.c").

Given the file debug-test.rb:
   def foo(n)
     n / 4
   end
   
   def bar(m)
     m*foo(m)
   end
   
   foo(10)
   bar('a')
   bar(122)

I can do, for example:
ruby -r mydebug debug-test.rb
debug-test.rb:1:def foo(n)
(rdb:-) c
undefined method `/' for "a"
        from debug-test.rb:2:in `foo'
        from debug-test.rb:6:in `bar'
        from debug-test.rb:10
debug-test.rb:2:  n / 4
(rdb:-) list
        1 def foo(n)
-->     2   n / 4
        3 end
        4 
        5 def bar(m)
        6   m*foo(m)
        7 end
        8 
        9 foo(10)
       10 bar('a')
       11 bar(122)
(rdb:-) where
-->  frame 2:debug-test.rb:2:in `foo'
     frame 1:debug-test.rb:6:in `bar'
     frame 0:debug-test.rb:10
(rdb:-) p n
"a"
(rdb:-) p m
./mydebug.rb:37:in `debug_eval':(eval):1:in `foo': undefined local
variable or m
ethod `m' for #<Object:0x40185ed4>
nil
(rdb:-) d
at level 1
(rdb:-) w
     frame 2:debug-test.rb:2:in `foo'
-->  frame 1:debug-test.rb:6:in `bar'
     frame 0:debug-test.rb:10
(rdb:-) list
        5 def bar(m)
-->     6   m*foo(m)
        7 end
        8 
        9 foo(10)
       10 bar('a')
       11 bar(122)
(rdb:-) p m
"a"
(rdb:-) p n
./mydebug.rb:37:in `debug_eval':(eval):1:in `bar': undefined local
variable or m
ethod `n' for #<Object:0x40185ed4>
nil
(rdb:-) d
at level 0
(rdb:-) list
        9 foo(10)
-->    10 bar('a')
       11 bar(122)
(rdb:-) c
debug-test.rb:2:in `foo': undefined method `/' for "a" (NameError)
        from debug-test.rb:6:in `bar'
        from debug-test.rb:10