title: Failed to migrate TF1 to TF2. pasta.base.annotate.AnnotationError: Expected ':' but found ')'
body: <p>So im currently need to upgrade my tf1 to tf2 and my directory is looks like this:</p>
  <pre><code>.
  ├─ tensorflow
  │     └─ models
  │         └─ (clone of https://github.com/tensorflow/models)
  .
  </code></pre>
  <p>I try upgrade it by using command <code>tf_upgrade_v2 --intree tensorflow/models/ --outtree tensorflow2/models/ --reportfile report.txt</code></p>
  <p>but this really long error i can not understand occur:</p>
  <pre><code>...
    File &quot;C:\Users\FOX\AppData\Local\Programs\Python\Python39\lib\site-packages\pasta\base\annotate.py&quot;, line 47, in wrapped
      f(self, node, *args, **kwargs)
    File &quot;C:\Users\FOX\AppData\Local\Programs\Python\Python39\lib\site-packages\pasta\base\annotate.py&quot;, line 1204, in visit_Slice
      self.attr(node, 'lowerspace', [self.ws, ':', self.ws], default=':')
    File &quot;C:\Users\FOX\AppData\Local\Programs\Python\Python39\lib\site-packages\pasta\base\annotate.py&quot;, line 1467, in attr
      attr_parts.append(self.token(attr_val))
    File &quot;C:\Users\FOX\AppData\Local\Programs\Python\Python39\lib\site-packages\pasta\base\annotate.py&quot;, line 1392, in token
      raise AnnotationError(&quot;Expected %r but found %r\nline %d: %s&quot; % (
  pasta.base.annotate.AnnotationError: Expected ':' but found ')'
  line 96:     im_mask[y_0:y_1, x_0:x_1] = mask[(y_0 - ref_box[1]):(y_1 - ref_box[1]),
  </code></pre>
  <p>Im sorry i don't know how to provide complete error message because it's way longer than my explanation</p>