problem with installation with the newest version 4.3.0.38 and python 3.6.8

[mkrajnak]

Expected behaviour

The older version works fine:

$ pip3 install --user opencv-python==4.2.0.34
Collecting opencv-python==4.2.0.34
  Downloading https://files.pythonhosted.org/packages/72/c2/e9cf54ae5b1102020ef895866a67cb2e1aef72f16dd1fde5b5fb1495ad9c/opencv_python-4.2.0.34-cp36-cp36m-manylinux1_x86_64.whl (28.2MB)
    100% |████████████████████████████████| 28.2MB 67kB/s 
Collecting numpy>=1.11.3 (from opencv-python==4.2.0.34)
  Downloading https://files.pythonhosted.org/packages/22/e7/4b2bdddb99f5f631d8c1de259897c2b7d65dcfcc1e0a6fd17a7f62923500/numpy-1.19.1-cp36-cp36m-manylinux1_x86_64.whl (13.4MB)
    100% |████████████████████████████████| 13.4MB 145kB/s 
Installing collected packages: numpy, opencv-python
Successfully installed numpy-1.19.1 opencv-python-4.2.0.34

Actual behaviour

$ pip3 install --user opencv-python 
Collecting opencv-python
  Using cached https://files.pythonhosted.org/packages/a1/d6/8422797e35f8814b1d9842530566a949d9b5850a466321a6c1d5a99055ee/opencv-python-4.3.0.38.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-467m552x/opencv-python/setup.py", line 9, in <module>
        import skbuild
    ModuleNotFoundError: No module named 'skbuild'

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-467m552x/opencv-python/

Steps to reproduce

$ pip3 install --user opencv-python 

this is happening on rhel8 (fresh install. no previous versions of opencv installed), python3 version:

python3                           
Python 3.6.8 (default, Jun 26 2020, 12:10:09) 
[GCC 8.3.1 20191121 (Red Hat 8.3.1-5)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Workarounds that I have tried (stack overflow):

$ pip3 install --user cmake scikit-build
....
$   pip3 install --user opencv-python            
Collecting opencv-python
  Using cached https://files.pythonhosted.org/packages/a1/d6/8422797e35f8814b1d9842530566a949d9b5850a466321a6c1d5a99055ee/opencv-python-4.3.0.38.tar.gz
Requirement already satisfied: numpy>=1.13.3 in /home/mkrajnak/.local/lib/python3.6/site-packages (from opencv-python)
Building wheels for collected packages: opencv-python
  Running setup.py bdist_wheel for opencv-python ... error
  Complete output from command /usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-78o09h7e/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/tmpvcmmhhevpip-wheel- --python-tag cp36:
  Traceback (most recent call last):
    File "/home/mkrajnak/.local/lib/python3.6/site-packages/skbuild/setuptools_wrap.py", line 560, in setup
      cmkr = cmaker.CMaker(cmake_executable)
    File "/home/mkrajnak/.local/lib/python3.6/site-packages/skbuild/cmaker.py", line 95, in __init__
      self.cmake_version = get_cmake_version(self.cmake_executable)
    File "/home/mkrajnak/.local/lib/python3.6/site-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: opencv-python
  Running setup.py install for opencv-python ... error
    Complete output from command /usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-78o09h7e/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-skxs1drk-record/install-record.txt --single-version-externally-managed --compile --user --prefix=:
    Traceback (most recent call last):
      File "/home/mkrajnak/.local/lib/python3.6/site-packages/skbuild/setuptools_wrap.py", line 560, in setup
        cmkr = cmaker.CMaker(cmake_executable)
      File "/home/mkrajnak/.local/lib/python3.6/site-packages/skbuild/cmaker.py", line 95, in __init__
        self.cmake_version = get_cmake_version(self.cmake_executable)
      File "/home/mkrajnak/.local/lib/python3.6/site-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

    ----------------------------------------
Command "/usr/bin/python3.6 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-78o09h7e/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-skxs1drk-record/install-record.txt --single-version-externally-managed --compile --user --prefix=" failed with error code 1 in /tmp/pip-build-78o09h7e/opencv-python/

I believe the python3.6 is supported, I am using the opencv-python==4.2.0.34 as a workaround for now, were there new dependencies added between the versions? Do I really need cmake to make opencv work?

If the issue is common, I am sorry I've spent some time on this a couldn't find anything helpful.

[skvark]

What's the version of pip? pip >= 19.3 is required for the two latest releases due to manylinux2014. Check the release notes: https://github.com/skvark/opencv-python/releases/tag/36

pip tries to compile from source because it does not find compatible pre-built wheels. Manylinux pip version requirement table is here: https://github.com/pypa/manylinux#manylinux

You can upgrade pip with (also found from the README of this repository): pip install --upgrade pip

[mkrajnak]

Yes you are right, I didn't notice that the machine comes with the older version of pip, sudo pip3 install --upgrade pip solved this for me. Thanks a lot !

[andreish]

please consider reopen:

docker build -t testo-opecv-python .

=========== Dockerfile ============== FROM ubuntu:18.04

ENV LANG=en_US.UTF-8 \ LC_ALL=en_US.UTF-8

RUN echo "$LOG_TAG update and install basic packages" && \ apt-get -y update && \ apt-get install -y locales apt-utils && \ locale-gen $LANG && update-locale $LANG && \ apt-get install -y software-properties-common && \ apt-get install -y build-essential pkg-config libffi-dev

RUN apt-get install -y python-pip

RUN pip install --upgrade pip && \ pip --version && \ pip install wheel && \ pip install opencv-python

==================================

this fails to build with:

/pip.pypa.io/en/latest/development/release-process/#python-2-support Collecting opencv-python Downloading opencv-python-4.3.0.38.tar.gz (88.0 MB) Installing build dependencies: started Installing build dependencies: finished with status 'done' Getting requirements to build wheel: started Getting requirements to build wheel: finished with status 'error' ERROR: Command errored out with exit status 1: command: /usr/bin/python /usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpkrD0Rd cwd: /tmp/pip-install-MC24hE/opencv-python Complete output (22 lines): Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py", line 280, in main() File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py", line 263, in main json_out['return_val'] = hook(**hook_input['kwargs']) File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py", line 114, in get_requires_for_build_wheel return hook(config_settings) File "/tmp/pip-build-env-nV6VDw/overlay/lib/python2.7/site-packages/setuptools/build_meta.py", line 146, in get_requires_for_build_wheel return self._get_build_requires(config_settings, requirements=['wheel']) File "/tmp/pip-build-env-nV6VDw/overlay/lib/python2.7/site-packages/setuptools/build_meta.py", line 127, in _get_build_requires self.run_setup() File "/tmp/pip-build-env-nV6VDw/overlay/lib/python2.7/site-packages/setuptools/build_meta.py", line 243, in run_setup self).run_setup(setup_script=setup_script) File "/tmp/pip-build-env-nV6VDw/overlay/lib/python2.7/site-packages/setuptools/build_meta.py", line 142, in run_setup exec(compile(code, file, 'exec'), locals()) File "setup.py", line 448, in main() File "setup.py", line 99, in main % {"ext": re.escape(sysconfig.get_config_var("EXT_SUFFIX"))} File "/usr/lib/python2.7/re.py", line 210, in escape s = list(pattern) TypeError: 'NoneType' object is not iterable

ERROR: Command errored out with exit status 1: /usr/bin/python /usr/local/lib/python2.7/dist-packages/pip/_vendor/pep517/_in_process.py get_requires_for_build_wheel /tmp/tmpkrD0Rd Check the logs for full command output. The command '/bin/sh -c pip install --upgrade pip && pip --version && pip install wheel && pip install opencv-python' returned a non-zero code: 1

This works

FROM ubuntu:18.04

ENV LANG=en_US.UTF-8 \ LC_ALL=en_US.UTF-8

RUN echo "$LOG_TAG update and install basic packages" && \ apt-get -y update && \ apt-get install -y locales apt-utils && \ locale-gen $LANG && update-locale $LANG && \ apt-get install -y software-properties-common && \ apt-get install -y build-essential pkg-config libffi-dev

RUN apt-get install -y python-pip

RUN pip install --upgrade pip && \ pip --version && \ pip install wheel && \ pip install opencv-python==4.2.0.32

last week I could build with latest 4.3.0.36 and got a container with

root@92f802180a93:/zeppelin# pip list | grep opencv opencv-python 4.3.0.36

[skvark]

Python 2.7 hasn't been supported since 4.3.0.36. Your pip points most likely to Python 2.7. Use pip3 instead. There is no Python 2.7 wheels for 4.3.0.36 or source distribution (https://pypi.org/project/opencv-python/4.3.0.36/#files) so you must have used Python 3 for that working version.

[andreish]

Thank you, using pip3 fixes it .