Evaluate code in the context from which exception was thrown

gistfile1.rb

# http://stackoverflow.com/questions/106920/how-can-i-get-source-and-variable-values-in-ruby-tracebacks

class StandardError
  alias_method :initialize_old, :initialize
  
  attr_reader :binding
  
  def initialize(*args)
    initialize_old *args
    
    file, line = caller(1).first.split(':')[0,2]
    line = line.to_i
    
    set_trace_func(proc do |ev,f,l,id,binding,classname|
      if f == file && l == line
        @binding = binding
        set_trace_func nil
      end
    end)
  end
end

begin
  def foo
    bar
  end
  
  def bar
    a = 10
    b = 20
    raise RuntimeError, "yolo"
  end
  
  foo
rescue => e
  p e.message
  p e.backtrace
  p eval("local_variables", e.binding)
  p eval("a + b", e.binding)
end