```Bash
--- tons of backtrace ---
    res = getattr(self, methodname)(oparg, next_instr)
   File "/home/lsl/michel/prof/pypy/rpython/flowspace/flowcontext.py", line 871, in LOAD_FAST
    raise FlowingError(self, "Local variable referenced before assignment")
 FlowingError: -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Local variable referenced before assignment
<
Occurred processing the following simple_call:
      (KeyError getting at the binding!)
 v43 = simple_call((function multiline_comment__next), v42)
In <FunctionGraph of (rpython.flowspace.generator:70)GeneratorIterator.next at 0x154f2c98>:
Happened at file /home/lsl/michel/prof/pypy/rpython/flowspace/generator.py line 74

==>         (next_entry, return_value) = func(entry)

Known variable annotations:
 v42 = SomeInstance(can_be_None=False, classdef=rpython.flowspace.generator.Entry)>
In <FunctionGraph of (topaz.lexer:360)Lexer.multiline_comment__next at 0x196b3868>:
Happened at file topaz/lexer.py line 366

                for i in xrange(idx + 1):

Processing block:
 block@42 is a <class 'rpython.flowspace.flowcontext.SpamBlock'>
 in (rpython.flowspace.generator:70)GeneratorIterator.next
 containing the following operations:
       v43 = simple_call((function multiline_comment__next), v42)
       v44 = len(v43)
       v45 = eq(v44, (2))
       v46 = is_true(v45)
 --end--
```