old_contents: from SCons.Script import *
  
  
  def generate(env):
      env.SetDefault(RUN_DISTUTILS = 'python')
      env.SetDefault(RUN_DISTUTILSOPTS = 'build')
  
      env['RUN_DISTUTILS'] = 'python'
      env['RUN_DISTUTILSOPTS'] = 'build'
  
      bld = Builder(action = '$RUN_DISTUTILS $SOURCE $RUN_DISTUTILSOPTS')
      env.Append(BUILDERS = {'RunDistUtils' : bld})
  
  
  def exists():
      return 1
  
new_contents: from SCons.Script import *
  import os
  
  
  def generate(env):
      env.SetDefault(RUN_DISTUTILS = 'python')
      env.SetDefault(RUN_DISTUTILSOPTS = 'build')
  
      if 'RUN_DISTUTILS' in os.environ:
          env['RUN_DISTUTILS'] = os.environ['RUN_DISTUTILS']
      if 'RUN_DISTUTILSOPTS' in os.environ:
          env['RUN_DISTUTILSOPTS'] = os.environ['RUN_DISTUTILSOPTS']
  
      bld = Builder(action = '$RUN_DISTUTILS $SOURCE $RUN_DISTUTILSOPTS')
      env.Append(BUILDERS = {'RunDistUtils' : bld})
  
  
  def exists():
      return 1
  
subject: Allow env vars for RUN_DISTUTILS