old_contents: #!/usr/bin/env python
  
  from setuptools import setup
  
  setup(
      setup_requires=['d2to1', 'pbr'],
      d2to1=True,
  )
  
new_contents: #!/usr/bin/env python
  
  from setuptools import setup
  
  setup(
      setup_requires=['pbr'],
      pbr=True,
  )
  
subject: update use of pbr