old_contents: # content of conftest.py
  import pytest
  
  import qc18SV4
  
  
  def pytest_addoption(parser):
      parser.addoption("--uchime-ref-db-fp", action="store", required=True, help="path to PR2 database")
  
  
  @pytest.fixture
  def pipeline():
      return qc18SV4.pipeline.Pipeline(
          forward_reads_fp='',
          forward_primer='', reverse_primer='',
          min_overlap=0,
          uchime_ref_db_fp='',
          work_dp='', core_count=1
      )
  
  
  @pytest.fixture
  def uchime_ref_db_fp(request):
      return request.config.getoption("--uchime-ref-db-fp")
  
new_contents: # content of conftest.py
  import pytest
  
  import qc18SV4
  
  
  #def pytest_addoption(parser):
  #    parser.addoption("--uchime-ref-db-fp", action="store", required=True, help="path to PR2 database")
  
  
  @pytest.fixture
  def pipeline():
      return qc18SV4.pipeline.Pipeline(
          forward_reads_fp='',
          forward_primer='', reverse_primer='',
          min_overlap=0,
          uchime_ref_db_fp='',
          work_dp='', core_count=1
      )
  
  
  #@pytest.fixture
  #def uchime_ref_db_fp(request):
  #    return request.config.getoption("--uchime-ref-db-fp")
  
subject: remove --uchime-ref-db-fp