pytest ffi failure with a new port

Hi.

I am trying to get Wayland backend for x11-wm/qtile running, which
requires three new dependencies: https://codeberg.org/ei/ports/commits/branch/qtile

I want to use tests/ in ports (i.e. x11/py-xkbcommon), so I added:

+do-test:
+       @cd ${WRKSRC}/tests && ${PYTHON_CMD} -m pytest -v -rs
+

to the Makefile, but make test results in:

==================================== test session starts ====================================
platform freebsd14 -- Python 3.8.12, pytest-4.6.11, py-1.9.0, pluggy-0.13.1 -- /usr/local/bin/python3.8
cachedir: .pytest_cache
rootdir: /usr/local/poudriere/ports/main/x11/py-xkbcommon/work-py38/xkbcommon-0.4
collected 0 items / 1 errors

========================================== ERRORS ===========================================
____________________________ ERROR collecting tests/test_xkb.py _____________________________
ImportError while importing test module '/usr/local/poudriere/ports/main/x11/py-xkbcommon/work-py38/xkbcommon-0.4/tests/test_xkb.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
test_xkb.py:6: in <module>
    from xkbcommon import xkb
../xkbcommon/xkb.py:5: in <module>
    from xkbcommon._ffi import ffi, lib
E   ModuleNotFoundError: No module named 'xkbcommon._ffi'
!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 errors during collection !!!!!!!!!!!!!!!!!!!!!!!!!!
================================== 1 error in 0.16 seconds ==================================
*** Error code 2

I rg'ed the ports tree for various ways around this, but nothing worked,
including PYTHONPATH, etc.

I have no idea why it can't find 'xkbcommon._ffi'. This port links to
libxkbcommon, and the default x11-wm/qtile desktop with Wayland backend
*seems* to be working. The same happens for other two ports (*._ffi not
found).

Any idea what can be done with do-test?