irb(main):001:0> def me(foo)
irb(main):002:1>   if foo
irb(main):003:2>     $1
irb(main):004:2>   else
irb(main):005:2*     nil
irb(main):006:2>   end
irb(main):007:1> end
=> #<Rubinius::CompiledMethod me file=(irb)>
irb(main):008:0> exit
An exception occurred running IRB
    A thrown value from Kernel#throw (Rubinius::ThrownValue)
 
Backtrace:
 
Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000
0x00000001001037a4 in rubinius::ObjectHeader::type_id (this=0x0) at oop.hpp:352
352	      return obj_type_;