Some tests fail on FreeBSD

[yurivict]

==================================================================================== test session starts =====================================================================================
platform freebsd13 -- Python 3.8.11, pytest-4.6.11, py-1.9.0, pluggy-0.13.1
rootdir: /disk-samsung/freebsd-ports/math/py-PuLP/work-py38/PuLP-2.5.1
plugins: forked-1.0.2, cov-2.9.0, hypothesis-6.14.6, rerunfailures-10.1, timeout-1.4.2, xdist-1.32.0, mock-1.10.4, asyncio-0.10.0, flakes-4.0.1
collected 850 items                                                                                                                                                                          

pulp/tests/test_examples.py .F                                                                                                                                                         [  0%]
pulp/tests/test_pulp.py ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss [ 18%]
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========================================================================================== FAILURES ==========================================================================================
______________________________________________________________________________ Examples_DocsTests.test_examples ______________________________________________________________________________

self = <pulp.tests.test_examples.Examples_DocsTests testMethod=test_examples>, examples_dir = '../../examples'

    def test_examples(self, examples_dir="../../examples"):
        import importlib
    
        this_file = os.path.realpath(__file__)
        parent_dir = os.path.dirname(this_file)
        files = os.listdir(os.path.join(parent_dir, examples_dir))
        TMP_dir = "_tmp/"
        if not os.path.exists(TMP_dir):
            os.mkdir(TMP_dir)
        for f_name in files:
            if os.path.isdir(f_name):
                continue
            _f_name = "examples." + os.path.splitext(f_name)[0]
            os.chdir(TMP_dir)
>           importlib.import_module(_f_name)

../pulp/tests/test_examples.py:22: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/local/lib/python3.8/importlib/__init__.py:127: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
<frozen importlib._bootstrap>:1014: in _gcd_import
    ???
<frozen importlib._bootstrap>:991: in _find_and_load
    ???
<frozen importlib._bootstrap>:975: in _find_and_load_unlocked
    ???
<frozen importlib._bootstrap>:671: in _load_unlocked
    ???
<frozen importlib._bootstrap_external>:843: in exec_module
    ???
<frozen importlib._bootstrap>:219: in _call_with_frames_removed
    ???
../examples/SpongeRollProblem5.py:35: in <module>
    Patterns, morePatterns = subSolve(Patterns, duals)
../examples/CG.py:107: in subSolve
    [_vars[i] * duals[i] for i in Pattern.lenOpts]
../examples/CG.py:107: in <listcomp>
    [_vars[i] * duals[i] for i in Pattern.lenOpts]
../pulp/pulp.py:209: in __mul__
    return LpAffineExpression(self) * other
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = 1*Roll_Length_5 + 0, other = None

    def __mul__(self, other):
        e = self.emptyCopy()
        if isinstance(other, LpAffineExpression):
            e.constant = self.constant * other.constant
            if len(other):
                if len(self):
                    raise TypeError("Non-constant expressions cannot be multiplied")
                else:
                    c = self.constant
                    if c != 0:
                        for v, x in other.items():
                            e[v] = c * x
            else:
                c = other.constant
                if c != 0:
                    for v, x in self.items():
                        e[v] = c * x
        elif isinstance(other, LpVariable):
            return self * LpAffineExpression(other)
        else:
            if other != 0:
>               e.constant = self.constant * other
E               TypeError: unsupported operand type(s) for *: 'int' and 'NoneType'

../pulp/pulp.py:933: TypeError
------------------------------------------------------------------------------------ Captured stdout call ------------------------------------------------------------------------------------
GLPSOL--GLPK LP/MIP Solver 5.0
Parameter(s) specified in the command line:
 --cpxlp /tmp/faef3fec91f34bfe8bb4ea951ce85338-pulp.lp -o /tmp/faef3fec91f34bfe8bb4ea951ce85338-pulp.sol
Reading problem data from '/tmp/faef3fec91f34bfe8bb4ea951ce85338-pulp.lp'...
3 rows, 3 columns, 6 non-zeros
[...]
OPTIMAL SOLUTION FOUND BY LP PREPROCESSOR
Time used:   0.0 secs
Memory used: 0.0 Mb (32525 bytes)
Writing basic solution to '/tmp/dc329261598e4b29aed62776d258e913-pulp.sol'...
====================================================================================== warnings summary ======================================================================================
pulp/tests/test_examples.py::Examples_DocsTests::test_examples
  /disk-samsung/freebsd-ports/math/py-PuLP/work-py38/PuLP-2.5.1/pulp/pulp.py:1313: UserWarning: Spaces are not permitted in the name. Converted to '_'
    warnings.warn("Spaces are not permitted in the name. Converted to '_'")

-- Docs: https://docs.pytest.org/en/latest/warnings.html
=============================================================== 1 failed, 107 passed, 742 skipped, 1 warnings in 21.68 seconds ===============================================================
*** Error code 1

Version: 2.5.1
Python-3.8
OS: FreeBSD 13