message: Remove the pretty formatting of generated code. The astor library that did that uses circular references, which can be problematic in eager mode.
diff: @@ -57,8 +57,15 @@ def ast_to_source(node, indentation=' '):
  # In some versions of Python, literals may appear as actual values. This
  # ensures everything is string.
  - code = map(str, generator.result)
  - code = astor.source_repr.pretty_source(code).lstrip()
  + code = ''.join(map(str, generator.result))
  +
  + # Strip leading blank lines.
  + code_lines = code.split('\n')
  + trimmed_code_lines = []
  + for l in code_lines:
  + if l.rstrip() or trimmed_code_lines:
  + trimmed_code_lines.append(l)
  + code = '\n'.join(trimmed_code_lines)
  return code
  