I’ve got an issue with an undeclared dependency inside Python tests. I’ve got a test with a dependency that uses an underlying C++ Package: GDCM. Before pants we would perform a

conda install gdcm

inside of tox to run our tests. Without having access to Conda an alternative I’ve found is to use

python-gdcm

instead which is a Python wrapper for GDCM. I’ve tried to attach this dependency to the tests using a `python_requirement`:

python_requirement(
    name="gdcm",
    requirements=["python-gdcm"],
)

python_tests(
    name="tests",
    sources=[
        "tests/**/test_*.py",
        "tests/test_*.py",
    ],
    dependencies=[
        ":conftest",
        ":test-resources",
        ":gdcm",
    ],
)

However this doesn’t work and

python-gdcm

doesn’t get installed into the underlying testing PEXs unless I add this snippet to one of my test files:

try:
    import gdcm # noqa
except ImportError:
    pass

How can I have the tests depend on

python-gdcm

without the attempted import? Or alternatively, how can I give Pants access to the underlying gdcm binary (for example, one that was installed by brew or conda on the host system)?