After installing all requirements and installing my_module in editable mode with pip install -e ., pytest passes.

If I instead install my_module with pip install ., pytest fails with:

============================================ test session starts =============================================
platform darwin -- Python 3.9.5, pytest-7.1.0, pluggy-1.0.0
rootdir: /Users/X/my_module, configfile: pyproject.toml, testpaths: tests
plugins: cov-3.0.0
collected 13 items

tests/end_to_end/test_end_to_end_example.py .                                                          [  7%]
tests/integration/test_integration_example.py .                                                        [ 15%]
tests/unit/test_unit_example.py .                                                                      [ 23%]
tests/unit/test_weather.py ..........                                                                  [100%]/Users/X/my_module/lib/python3.9/site-packages/coverage/control.py:793: CoverageWarning: No data was collected. (no-data-collected)
  self._warn("No data was collected.", slug="no-data-collected")


---------- coverage: platform darwin, python 3.9.5-final-0 -----------
Name                    Stmts   Miss  Cover   Missing
-----------------------------------------------------
my_module/__init__.py        0      0   100%
my_module/constants.py       1      1     0%   4
my_module/calc.py           14     14     0%   4-54
-----------------------------------------------------
TOTAL                      15     15     0%

FAIL Required test coverage of 100.0% not reached. Total coverage: 0.00%

============================================= 13 passed in 0.31s =============================================

my_module has the following structure:

my_module
├── README.md
├── my_module
│   ├── __init__.py
│   ├── constants.py
│   ├── py.typed
│   └── calc.py
├── pyproject.toml
├── pyvenv.cfg
├── requirements.txt
├── setup.cfg
├── setup.py
└── tests
    ├── conftest.py
    ├── end_to_end
    │   └── test_end_to_end_example.py
    ├── integration
    │   └── test_integration_example.py
    ├── requirements.txt
    └── unit
        ├── test_unit_example.py
        └── test_calc.py

pyproject.toml:

[build-system]
# The assumed default build requirements from pip are: "setuptools>=40.8.0",
#     "wheel"
# See: https://pip.pypa.io/en/stable/reference/pip/#pep-517-and-518-support
# These are taken from the PyScaffold example
# See: https://github.com/pyscaffold/pyscaffold-demo
requires = ["setuptools>=46.1.0", "setuptools_scm[toml]>=5", "wheel"]
build-backend = "setuptools.build_meta"


[tool.coverage.run]
source = [
    "my_module/",
    "*/site-packages/"
]

[tool.coverage.report]
show_missing = true
fail_under = 100
exclude_lines = ["pragma: not covered", "@overload"]


[tool.pytest.ini_options]
addopts = "--cov=my_module"
testpaths = "tests"

setup.cfg:

[options]
zip_safe = False
include_package_data = True
packages = my_module
python_requires = >=3.7
install_requires =
    attrs >=21.2
    pandas >=1.3.4
    python-dateutil >=2.8
    requests >=2.26
    titlecase >=2.3

[options.extras_require]
tests =
    autoflake >=1.4
    black >=22.1
    flake8 >=4.0
    isort >=5.10
    mypy >=0.941
    pre-commit >=2.17
    pytest >=6.2
    pytest-cov >=3.0
    pyupgrade >=2.31