  # Environment Variable Cleanup
  
  Original TEST_CLEANUP_VAR: None
  Original ANOTHER_CLEANUP_VAR: None
  
  Running booktest with env vars set in config...
  Test run completed with exit code: 255
  
  Captured TEST_CLEANUP_VAR: temporary_value
  Captured ANOTHER_CLEANUP_VAR: another_temporary
  
  After execution TEST_CLEANUP_VAR in parent: None
  After execution ANOTHER_CLEANUP_VAR in parent: None
  
  ✓ Environment variables were properly isolated to subprocess!
