old_contents: import os, unittest
  
  """This module long_test provides a decorator, @long_test, that you can use to
  mark tests which take a lot of wall clock time.
  
  If the system environment variable SKIP_LONG_TESTS is set, tests decorated
  with @long_test will not be run.
  """
  
  SKIP_LONG_TESTS = os.getenv('SKIP_LONG_TESTS', None) is not None
  
  long_test = unittest.skipIf(SKIP_LONG_TESTS, 'Long tests skipped.')
  
new_contents: import os, unittest
  
  """This module long_test provides a decorator, @long_test, that you can use to
  mark tests which take a lot of wall clock time.
  
  If the system environment variable SKIP_LONG_TESTS is set, tests decorated
  with @long_test will not be run.
  """
  
  SKIP_LONG_TESTS = os.getenv('SKIP_LONG_TESTS', '').lower().startswith('t')
  
  long_test = unittest.skipIf(SKIP_LONG_TESTS, 'Long tests skipped.')
  
subject: Improve handling of SKIP_LONG_TESTS build variable.