Installing OpenCV fails because it cannot find "skbuild"

Question

I have a docker image that I need to install openCV in it and from yesterday it started to fail because it cannot find the "skbuild" module:

Step 12/24 : RUN pip install opencv-python opencv-contrib-python  ---> Running in a0f746a23aed Collecting opencv-python   Downloading https://files.pythonhosted.org/packages/77/f5/49f034f8d109efcf9b7e98fbc051878b83b2f02a1c73f92bbd37f317288e/opencv-python-4.4.0.42.tar.gz (88.9MB)     Complete output from command python setup.py egg_info:     Traceback (most recent call last):       File "<string>", line 1, in <module>       File "/tmp/pip-build-cciracwm/opencv-python/setup.py", line 9, in <module>         import skbuild     ModuleNotFoundError: No module named 'skbuild' 

And on the host also I cannot find that module and pip search is either return nothing or returns a server error:

sudo pip3 search skbuild WARNING: The directory '/home/ali/.cache/pip' or its parent directory is not owned or is not writable by the current user. The cache has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. ERROR: Exception: Traceback (most recent call last):   File "/usr/local/lib/python3.6/dist-packages/pip/_internal/cli/base_command.py", line 216, in _main     status = self.run(options, args)   File "/usr/local/lib/python3.6/dist-packages/pip/_internal/commands/search.py", line 60, in run     pypi_hits = self.search(query, options)   File "/usr/local/lib/python3.6/dist-packages/pip/_internal/commands/search.py", line 80, in search     hits = pypi.search({'name': query, 'summary': query}, 'or')   File "/usr/lib/python3.6/xmlrpc/client.py", line 1112, in __call__     return self.__send(self.__name, args)   File "/usr/lib/python3.6/xmlrpc/client.py", line 1452, in __request     verbose=self.__verbose   File "/usr/local/lib/python3.6/dist-packages/pip/_internal/network/xmlrpc.py", line 45, in request     return self.parse_response(response.raw)   File "/usr/lib/python3.6/xmlrpc/client.py", line 1342, in parse_response     return u.close()   File "/usr/lib/python3.6/xmlrpc/client.py", line 656, in close     raise Fault(**self._stack[0]) xmlrpc.client.Fault: <Fault -32403: 'server error; service unavailable'> 

Is this because their server has some problems or it is related to my pip?

Update

I tried it on different python and pip versions, python versions 3.6 and 3.7 and pip version 19.12 and 20.2.2 and 9.0.1 (the one inside image).

Update 2

I added pip install scikit-build one step before opencv installation but I get another error related to cmake:

Step 12/25 : RUN pip install scikit-build  ---> Running in afe0c5c0fca0 Collecting scikit-build   Downloading https://files.pythonhosted.org/packages/78/c9/7c2c7397ea64e36ebb292446896edcdecbb8c1aa6b9a1a32f6f67984c3df/scikit_build-0.11.1-py2.py3-none-any.whl (72kB) Collecting packaging (from scikit-build)   Downloading https://files.pythonhosted.org/packages/46/19/c5ab91b1b05cfe63cccd5cfc971db9214c6dd6ced54e33c30d5af1d2bc43/packaging-20.4-py2.py3-none-any.whl Requirement already satisfied: wheel>=0.29.0 in /usr/lib/python3/dist-packages (from scikit-build) Collecting distro (from scikit-build)   Downloading https://files.pythonhosted.org/packages/25/b7/b3c4270a11414cb22c6352ebc7a83aaa3712043be29daa05018fd5a5c956/distro-1.5.0-py2.py3-none-any.whl Requirement already satisfied: setuptools>=28.0.0; python_version >= "3" in /usr/lib/python3/dist-packages (from scikit-build) Requirement already satisfied: six in /usr/lib/python3/dist-packages (from packaging->scikit-build) Collecting pyparsing>=2.0.2 (from packaging->scikit-build)   Downloading https://files.pythonhosted.org/packages/8a/bb/488841f56197b13700afd5658fc279a2025a39e22449b7cf29864669b15d/pyparsing-2.4.7-py2.py3-none-any.whl (67kB) Installing collected packages: pyparsing, packaging, distro, scikit-build Successfully installed distro-1.5.0 packaging-20.4 pyparsing-2.4.7 scikit-build-0.11.1 Removing intermediate container afe0c5c0fca0  ---> 533658ddf26d Step 13/25 : RUN pip install opencv-python opencv-contrib-python  ---> Running in 0f2c03bc042a Collecting opencv-python   Downloading https://files.pythonhosted.org/packages/77/f5/49f034f8d109efcf9b7e98fbc051878b83b2f02a1c73f92bbd37f317288e/opencv-python-4.4.0.42.tar.gz (88.9MB) Collecting opencv-contrib-python   Downloading https://files.pythonhosted.org/packages/48/98/05bd8e00c71b66c4e7847cc051cac404191d904df58b51a7dcc3767ff747/opencv_contrib_python-4.2.0.34-cp37-cp37m-manylinux1_x86_64.whl (34.2MB) Collecting numpy>=1.14.5 (from opencv-python)   Downloading https://files.pythonhosted.org/packages/3d/d1/90cd7e0b27ee86d77f5386d38b74520486100286d50772377791b6ef22ff/numpy-1.19.1-cp37-cp37m-manylinux1_x86_64.whl (13.4MB) Building wheels for collected packages: opencv-python   Running setup.py bdist_wheel for opencv-python: started   Running setup.py bdist_wheel for opencv-python: finished with status 'error'   Complete output from command /usr/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-w49xv99a/opencv-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /tmp/tmpycj03zlwpip-wheel- --python-tag cp37:   /usr/lib/python3.7/distutils/dist.py:274: UserWarning: Unknown distribution option: 'long_description_content_type'     warnings.warn(msg)   Traceback (most recent call last):     File "/usr/local/lib/python3.7/dist-packages/skbuild/setuptools_wrap.py", line 560, in setup       cmkr = cmaker.CMaker(cmake_executable)     File "/usr/local/lib/python3.7/dist-packages/skbuild/cmaker.py", line 95, in __init__       self.cmake_version = get_cmake_version(self.cmake_executable)     File "/usr/local/lib/python3.7/dist-packages/skbuild/cmaker.py", line 82, in get_cmake_version       "Problem with the CMake installation, aborting build. CMake executable is %s" % cmake_executable)      Problem with the CMake installation, aborting build. CMake executable is cmake      ----------------------------------------   Failed building wheel for opencv-python   Running setup.py clean for opencv-python Failed to build opencv-python Installing collected packages: numpy, opencv-python, opencv-contrib-python   Found existing installation: numpy 1.13.3     Not uninstalling numpy at /usr/lib/python3/dist-packages, outside environment /usr   Running setup.py install for opencv-python: started     Running setup.py install for opencv-python: finished with status 'error'     Complete output from command /usr/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-w49xv99a/opencv-python/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-maky1uyw-record/install-record.txt --single-version-externally-managed --compile:     /usr/lib/python3.7/distutils/dist.py:274: UserWarning: Unknown distribution option: 'long_description_content_type'       warnings.warn(msg)     Traceback (most recent call last):       File "/usr/local/lib/python3.7/dist-packages/skbuild/setuptools_wrap.py", line 560, in setup         cmkr = cmaker.CMaker(cmake_executable)       File "/usr/local/lib/python3.7/dist-packages/skbuild/cmaker.py", line 95, in __init__         self.cmake_version = get_cmake_version(self.cmake_executable)       File "/usr/local/lib/python3.7/dist-packages/skbuild/cmaker.py", line 82, in get_cmake_version         "Problem with the CMake installation, aborting build. CMake executable is %s" % cmake_executable)          Problem with the CMake installation, aborting build. CMake executable is cmake 

Answer 1

If you read the opencv-python package FAQ in PyPI, it clearly provides an answer for this specific issue: you must run pip install --upgrade pip. Check pip version afterwards with pip -V.

This is because your pip is too old to understand the new manylinux2014 package format and tries to compile from source. That will also fail because pip is too old to understand how to use pyproject.toml to install build dependencies such as scikit-build.

Another issue I'm spotting is that you install both opencv-python and opencv-contrib-python. You should not do this. It's also explained in the PyPI page of the packages. Most likely you should be using just opencv-contrib-python-headless package since you are using Docker and I assume you do not use the GUI functionalities of OpenCV.