First output of pytest:

INFO:setup:if error `unknown file type '.pyx'` occurs try `pip install cython` and rerun
running pytest
Searching for mock
Reading https://pypi.org/simple/mock/
Downloading https://files.pythonhosted.org/packages/05/d2/f94e68be6b17f46d2c353564da56e6fb89ef09faeeff3313a046cb810ca9/mock-3.0.5-py2.py3-none-any.whl#sha256=d157e52d4e5b938c550f39eb2fd15610db062441a9c2747d3dbfa9298211d0f8
Best match: mock 3.0.5
Processing mock-3.0.5-py2.py3-none-any.whl
Installing mock-3.0.5-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\mock-3.0.5-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\mock-3.0.5-py3.7.egg
Searching for pytest<5
Reading https://pypi.org/simple/pytest/
Downloading https://files.pythonhosted.org/packages/64/f1/187a98b8f913a8f3a53d213cca2fae19718565f36165804d7f4f91fe5b76/pytest-4.6.6-py2.py3-none-any.whl#sha256=5d0d20a9a66e39b5845ab14f8989f3463a7aa973700e6cdf02db69da9821e738
Best match: pytest 4.6.6
Processing pytest-4.6.6-py2.py3-none-any.whl
Installing pytest-4.6.6-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\pytest-4.6.6-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\pytest-4.6.6-py3.7.egg
Searching for six
Reading https://pypi.org/simple/six/
Downloading https://files.pythonhosted.org/packages/73/fb/00a976f728d0d1fecfe898238ce23f502a721c0ac0ecfedb80e0d88c64e9/six-1.12.0-py2.py3-none-any.whl#sha256=3350809f0555b11f552448330d0b52d5f24c91a322ea4a15ef22629740f3761c
Best match: six 1.12.0
Processing six-1.12.0-py2.py3-none-any.whl
Installing six-1.12.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\six-1.12.0-py3.7.egg
Searching for wcwidth
Reading https://pypi.org/simple/wcwidth/
Downloading https://files.pythonhosted.org/packages/7e/9f/526a6947247599b084ee5232e4f9190a38f398d7300d866af3ab571a5bfe/wcwidth-0.1.7-py2.py3-none-any.whl#sha256=f4ebe71925af7b40a864553f761ed559b43544f8f71746c2d756c7fe788ade7c
Best match: wcwidth 0.1.7
Processing wcwidth-0.1.7-py2.py3-none-any.whl
Installing wcwidth-0.1.7-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\wcwidth-0.1.7-py3.7.egg
Searching for py>=1.5.0
Reading https://pypi.org/simple/py/
Downloading https://files.pythonhosted.org/packages/76/bc/394ad449851729244a97857ee14d7cba61ddb268dce3db538ba2f2ba1f0f/py-1.8.0-py2.py3-none-any.whl#sha256=64f65755aee5b381cea27766a3a147c3f15b9b6b9ac88676de66ba2ae36793fa
Best match: py 1.8.0
Processing py-1.8.0-py2.py3-none-any.whl
Installing py-1.8.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\py-1.8.0-py3.7.egg
Searching for pluggy<1.0,>=0.12
Reading https://pypi.org/simple/pluggy/
Downloading https://files.pythonhosted.org/packages/92/c7/48439f7d5fd6bddb4c04b850bb862b42e3e2b98570040dfaf68aedd8114b/pluggy-0.13.0-py2.py3-none-any.whl#sha256=0db4b7601aae1d35b4a033282da476845aa19185c1e6964b25cf324b5e4ec3e6
Best match: pluggy 0.13.0
Processing pluggy-0.13.0-py2.py3-none-any.whl
Installing pluggy-0.13.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\pluggy-0.13.0-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\pluggy-0.13.0-py3.7.egg
Searching for packaging
Reading https://pypi.org/simple/packaging/
Downloading https://files.pythonhosted.org/packages/cf/94/9672c2d4b126e74c4496c6b3c58a8b51d6419267be9e70660ba23374c875/packaging-19.2-py2.py3-none-any.whl#sha256=d9551545c6d761f3def1677baf08ab2a3ca17c56879e70fecba2fc4dde4ed108
Best match: packaging 19.2
Processing packaging-19.2-py2.py3-none-any.whl
Installing packaging-19.2-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\packaging-19.2-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\packaging-19.2-py3.7.egg
Searching for more-itertools>=4.0.0
Reading https://pypi.org/simple/more-itertools/
Downloading https://files.pythonhosted.org/packages/45/dc/3241eef99eb45f1def35cf93af35d1cf9ef4c0991792583b8f33ea41b092/more_itertools-7.2.0-py3-none-any.whl#sha256=92b8c4b06dac4f0611c0729b2f2ede52b2e1bac1ab48f089c7ddc12e26bb60c4
Best match: more-itertools 7.2.0
Processing more_itertools-7.2.0-py3-none-any.whl
Installing more_itertools-7.2.0-py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\more_itertools-7.2.0-py3.7.egg
Searching for importlib-metadata>=0.12
Reading https://pypi.org/simple/importlib-metadata/
Downloading https://files.pythonhosted.org/packages/f6/d2/40b3fa882147719744e6aa50ac39cf7a22a913cbcba86a0371176c425a3b/importlib_metadata-0.23-py2.py3-none-any.whl#sha256=d5f18a79777f3aa179c145737780282e27b508fc8fd688cb17c7a813e8bd39af
Best match: importlib-metadata 0.23
Processing importlib_metadata-0.23-py2.py3-none-any.whl
Installing importlib_metadata-0.23-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\importlib_metadata-0.23-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\importlib_metadata-0.23-py3.7.egg
Searching for colorama
Reading https://pypi.org/simple/colorama/
Downloading https://files.pythonhosted.org/packages/4f/a6/728666f39bfff1719fc94c481890b2106837da9318031f71a8424b662e12/colorama-0.4.1-py2.py3-none-any.whl#sha256=f8ac84de7840f5b9c4e3347b3c1eaa50f7e49c2b07596221daec5edaabbd7c48
Best match: colorama 0.4.1
Processing colorama-0.4.1-py2.py3-none-any.whl
Installing colorama-0.4.1-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\colorama-0.4.1-py3.7.egg
Searching for attrs>=17.4.0
Reading https://pypi.org/simple/attrs/
Downloading https://files.pythonhosted.org/packages/a2/db/4313ab3be961f7a763066401fb77f7748373b6094076ae2bda2806988af6/attrs-19.3.0-py2.py3-none-any.whl#sha256=08a96c641c3a74e44eb59afb61a24f2cb9f4d7188748e76ba4bb5edfa3cb7d1c
Best match: attrs 19.3.0
Processing attrs-19.3.0-py2.py3-none-any.whl
Installing attrs-19.3.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\attrs-19.3.0-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\attrs-19.3.0-py3.7.egg
Searching for atomicwrites>=1.0
Reading https://pypi.org/simple/atomicwrites/
Downloading https://files.pythonhosted.org/packages/52/90/6155aa926f43f2b2a22b01be7241be3bfd1ceaf7d0b3267213e8127d41f4/atomicwrites-1.3.0-py2.py3-none-any.whl#sha256=03472c30eb2c5d1ba9227e4c2ca66ab8287fbfbbda3888aa93dc2e28fc6811b4
Best match: atomicwrites 1.3.0
Processing atomicwrites-1.3.0-py2.py3-none-any.whl
Installing atomicwrites-1.3.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\atomicwrites-1.3.0-py3.7.egg
Searching for pyparsing>=2.0.2
Reading https://pypi.org/simple/pyparsing/
Downloading https://files.pythonhosted.org/packages/11/fa/0160cd525c62d7abd076a070ff02b2b94de589f1a9789774f17d7c54058e/pyparsing-2.4.2-py2.py3-none-any.whl#sha256=d9338df12903bbf5d65a0e4e87c2161968b10d2e489652bb47001d82a9b028b4
Best match: pyparsing 2.4.2
Processing pyparsing-2.4.2-py2.py3-none-any.whl
Installing pyparsing-2.4.2-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\pyparsing-2.4.2-py3.7.egg
Searching for zipp>=0.5
Reading https://pypi.org/simple/zipp/
Downloading https://files.pythonhosted.org/packages/74/3d/1ee25a26411ba0401b43c6376d2316a71addcc72ef8690b101b4ea56d76a/zipp-0.6.0-py2.py3-none-any.whl#sha256=f06903e9f1f43b12d371004b4ac7b06ab39a44adc747266928ae6debfa7b3335
Best match: zipp 0.6.0
Processing zipp-0.6.0-py2.py3-none-any.whl
Installing zipp-0.6.0-py2.py3-none-any.whl to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs
writing requirements to c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\zipp-0.6.0-py3.7.egg\EGG-INFO\requires.txt

Installed c:\users\User\documents\personnal_folders\Name\spectrometer_project\python-seabreeze\.eggs\zipp-0.6.0-py3.7.egg
running egg_info
creating src\seabreeze.egg-info
writing src\seabreeze.egg-info\PKG-INFO
writing dependency_links to src\seabreeze.egg-info\dependency_links.txt
writing entry points to src\seabreeze.egg-info\entry_points.txt
writing requirements to src\seabreeze.egg-info\requires.txt
writing top-level names to src\seabreeze.egg-info\top_level.txt
writing manifest file 'src\seabreeze.egg-info\SOURCES.txt'
reading manifest template 'MANIFEST.in'
writing manifest file 'src\seabreeze.egg-info\SOURCES.txt'
running build_ext
building 'seabreeze.cseabreeze._wrapper' extension
error: Don't know how to compile src\seabreeze\cseabreeze\c_seabreeze_wrapper.pyx