pylint #9215 false undefined variable error in lambda function [resolved]

"""Demonstrate false undefined variable for lambda functions."""

def decorator(expr):
  """Function returning decorator."""
  def func(function):
     """Pass-thru decorator."""
     return function
  # use expr
  expr(0)
  return func

# this lambda is flagged
# E0602:  16:main.<lambda>: Undefined variable 'x'
@decorator(lambda x: x > 0)
def main():
  """Dummy function."""
  # this one is not flagged
  decorator(lambda y: y > 0)

if __name__ == "__main__":
  main()