Python 2.7.16

Traceback (most recent call last):
  File "bin/oil.py", line 61, in <module>
    callgraph.Walk(main, sys.modules)
  File "/home/uke/oil/opy/callgraph.py", line 490, in Walk
    _Walk(main, None, ['main'], syms)
  File "/home/uke/oil/opy/callgraph.py", line 243, in _Walk
    _Walk(val, None, ref, syms)
  File "/home/uke/oil/opy/callgraph.py", line 243, in _Walk
    _Walk(val, None, ref, syms)
  File "/home/uke/oil/opy/callgraph.py", line 243, in _Walk
    _Walk(val, None, ref, syms)
  File "/home/uke/oil/opy/callgraph.py", line 260, in _Walk
    _Walk(func_obj, cls, ref, syms)
  File "/home/uke/oil/opy/callgraph.py", line 206, in _Walk
    val = _GetAttr(module, var)
  File "/home/uke/oil/opy/callgraph.py", line 103, in _GetAttr
    val = getattr(__builtin__, name)
AttributeError: 'module' object has no attribute 'e_usage'