$ grep -A17 "def bzr_clone" swh/loader/bzr/loader.py
def bzr_clone(origin_url: str, repo_directory: str) -> Callable:
    """Bazaar clone function"""
    # try:
    #     from breezy.builtins import cmd_clone
    #     closure_clone = partial(cmd_clone().run, origin_url, repo_directory)
    # except ImportError:
    #     # stable python3.breezy does not define the cmd_clone yet
    #     # fallback
    #     def closure_clone():
    #         from subprocess import run
    #         run(["bzr", "clone", origin_url, repo_directory])
    # stable python3.breezy does not define the cmd_clone yet
    # fallback
    def closure_clone():
        from subprocess import run
        run(["bzr", "clone", origin_url, repo_directory])

    return closure_clone
$ pytest --ff -x -s swh/loader/bzr/tests
============================================================================================================= test session starts =============================================================================================================
platform linux -- Python 3.9.2, pytest-6.2.5, py-1.10.0, pluggy-1.0.0
rootdir: /home/tony/work/inria/repo/swh/swh-environment/swh-loader-bzr, configfile: pytest.ini
plugins: redis-2.1.1, forked-1.3.0, asyncio-0.15.1, django-4.4.0, django-test-migrations-1.1.0, requests-mock-1.9.3, flask-1.2.0, celery-0.0.0, mock-3.6.1, hypothesis-6.21.0, postgresql-2.6.1, dash-2.0.0, xdist-2.3.0, swh.core-1.1.1, swh.journal-1.0.0
collected 14 items
run-last-failure: no previously failed tests, not deselecting items.

swh/loader/bzr/tests/test_loader.py   create_plpgsql_language
----------------------------
 language already installed
(1 row)

Created new control directory.
............
swh/loader/bzr/tests/test_tasks.py [2022-02-09 14:34:04,653: INFO/MainProcess] Connected to memory://guest@localhost//
[2022-02-09 14:34:05,661: INFO/MainProcess] Task celery.ping[9f1f8a6b-0460-448b-b57c-0839b1b3c624] received
[2022-02-09 14:34:05,663: INFO/MainProcess] Task celery.ping[9f1f8a6b-0460-448b-b57c-0839b1b3c624] succeeded in 0.0013701990028494038s: 'pong'
[2022-02-09 14:34:06,665: INFO/MainProcess] Task swh.loader.bzr.tasks.LoadBazaar[45864edb-90cd-4c48-ba5d-3e04c281e97e] received
[2022-02-09 14:34:06,672: INFO/MainProcess] Task swh.loader.bzr.tasks.LoadBazaar[45864edb-90cd-4c48-ba5d-3e04c281e97e] succeeded in 0.006103710002207663s: {'status': 'eventful'}
.

============================================================================================================== warnings summary ===============================================================================================================
swh/loader/bzr/tests/test_tasks.py::test_loader
  /home/tony/.virtualenvs/swh/lib/python3.9/site-packages/mercurial/utils/resourceutil.py:12: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
    import imp

-- Docs: https://docs.pytest.org/en/stable/warnings.html
======================================================================================================== 14 passed, 1 warning in 7.94s ========================================================================================================