The slipcover.tracker module seems to be unimportable when using the Windows py38 binary wheel on Windows 10

I created a new virtualenv using Python 3.8 on Windows 10 and installed slipcover into it, using the wheel from PyPI.

On running python -m slipcover

Traceback (most recent call last):
  File "C:\Users\vagrant\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 192, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "C:\Users\vagrant\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Users\vagrant\py38\lib\site-packages\slipcover\__main__.py", line 4, in <module>
    from slipcover import slipcover as sc
  File "C:\Users\vagrant\py38\lib\site-packages\slipcover\slipcover.py", line 8, in <module>
    from . import tracker
ImportError: DLL load failed while importing tracker: The specified module could not be found.

The tracker module exists in the filesystem:

(py38) PS C:\Users\vagrant> dir .\py38\lib\site-packages\slipcover\


    Directory: C:\Users\vagrant\py38\lib\site-packages\slipcover


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----         4/27/2022  11:17 PM                __pycache__
-a----         4/27/2022  11:17 PM          27122 slipcover.py
-a----         4/27/2022  11:17 PM          14848 tracker.pyd
-a----         4/27/2022  11:17 PM              0 __init__.py
-a----         4/27/2022  11:17 PM           7287 __main__.py

[jaltmayerpizzorno]

Nice! Thank you for your help.

[exarkun]

Aha. Success -

(py38) PS C:\Users\vagrant> pip install -i https://test.pypi.org/simple/ slipcover==0.1.2.dev202204291210
Looking in indexes: https://test.pypi.org/simple/
Collecting slipcover==0.1.2.dev202204291210
  Downloading https://test-files.pythonhosted.org/packages/c6/e9/e9c1b5e080a7b1945e08ae53e149369b6184858bce74060a173b092e6adb/slipcover-0.1.2.dev202204291210-cp38-cp38-win_amd64.whl (78 kB)
     ---------------------------------------- 79.0/79.0 KB 1.5 MB/s eta 0:00:00
Requirement already satisfied: tabulate in c:\users\vagrant\py38\lib\site-packages (from slipcover==0.1.2.dev202204291210) (0.8.9)
Installing collected packages: slipcover
Successfully installed slipcover-0.1.2.dev202204291210
(py38) PS C:\Users\vagrant> python -m slipcover
usage: slipcover [-h] [--json] [--pretty-print] [--out OUT] [--source SOURCE] [--omit OMIT] [--threshold T] (-m MODULE | script) ...
slipcover: error: one of the arguments -m script is required
(py38) PS C:\Users\vagrant> python -m slipcover -m twisted.trial _zkapauthorizer.tests.test_pricecalculator
_zkapauthorizer
  tests
    test_pricecalculator ...                                            [ERROR]

===============================================================================
[ERROR]
Traceback (most recent call last):
  File "C:\Users\vagrant\py38\lib\site-packages\twisted\trial\runner.py", line 691, in loadByName
    return self.suiteFactory([self.findByName(name, recurse=recurse)])
  File "C:\Users\vagrant\py38\lib\site-packages\twisted\trial\runner.py", line 451, in findByName
    obj = reflect.namedModule(searchName)
  File "C:\Users\vagrant\py38\lib\site-packages\twisted\python\reflect.py", line 156, in namedModule
    topLevel = __import__(name)
  File "C:\Users\vagrant\py38\lib\site-packages\slipcover\__main__.py", line 26, in exec_module
    exec(code, module.__dict__)
  File "c:\users\vagrant\zkapauthorizer\src\_zkapauthorizer\tests\__init__.py", line 69, in <module>
    _configure_hypothesis()
  File "c:\users\vagrant\zkapauthorizer\src\_zkapauthorizer\tests\__init__.py", line 27, in _configure_hypothesis
    from hypothesis import HealthCheck, settings
builtins.ModuleNotFoundError: No module named 'hypothesis'

_zkapauthorizer.tests.test_pricecalculator
-------------------------------------------------------------------------------
Ran 1 tests in 0.047s

FAILED (errors=1)

File                                                    #lines    #missed    Cover%  Lines missing
----------------------------------------------------  --------  ---------  --------  -------------------------------------------------------------------------------------------------------
zkapauthorizer\src\_zkapauthorizer\__init__.py               6          0       100
zkapauthorizer\src\_zkapauthorizer\_version.py              24          9        62  29, 31-36, 39, 41
zkapauthorizer\src\_zkapauthorizer\tests\__init__.py        41         36        12  29-30, 36, 39, 42, 44, 48-49, 52, 54, 60-61, 64-66, 72, 74-76, 78-83, 85-86, 89-91, 95-97, 99, 101, 104