Issue 1:
System information (version)

OpenCV => 4.1.0

Operating System / Platform => Linux 4.4.0

Compiler => See below

Detailed description

On a multi-core system, setNumThreads doesn't seem to be taken into account. No matter what I try, my code and dependencies will spawn N threads whenever I call cv2 functions, where N is the number of cores on the machine.

We're already taking care of parallelism by creating as many processes as we have cores (python code), so we don't need OpenCV to spawn threads on top of that in the background, it only creates more CPU contention.

Steps to reproduce

>>> import cv2
>>> cv2.setNumThreads(1)
>>> c = cv2.VideoCapture('/path/to/video/file')

At this point a ps -eLf in another terminal will show as many python threads as there are cores on the machine, instead of only 1 as per setNumThreads(1).

So for instance on a machine with 64 cores, creating 64 processes (e.g. with multiprocessing.Process) will create 4096 threads in the background. Definitely not what we want. Creating only 1 process and 64 threads results in very poor performance as we have higher level work we need to parallelize.

NB: I've tried export OMP_NUM_THREADS=1, it doesn't seem to help either.

** SYSTEM AND BUILD INFO (this is a Deep Learning AMI on EC2)**

$ python
Python 3.6.6 |Anaconda, Inc.| (default, Jun 28 2018, 17:14:51)
[GCC 7.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2
>>> print(cv2.getBuildInformation())

General configuration for OpenCV 4.1.0 =====================================
Version control: 4.1.0

Extra modules:
Location (extra): /io/opencv_contrib/modules
Version control (extra): 4.1.0

Platform:
Timestamp: 2019-04-11T17:07:54Z
Host: Linux 4.4.0-101-generic x86_64
CMake: 3.9.0
CMake generator: Unix Makefiles
CMake build tool: /usr/bin/gmake
Configuration: Release

CPU/HW features:
Baseline: SSE SSE2 SSE3
requested: SSE3
Dispatched code generation: SSE4_1 SSE4_2 FP16 AVX AVX2
requested: SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX
SSE4_1 (13 files): + SSSE3 SSE4_1
SSE4_2 (1 files): + SSSE3 SSE4_1 POPCNT SSE4_2
FP16 (0 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX
AVX (4 files): + SSSE3 SSE4_1 POPCNT SSE4_2 AVX
AVX2 (27 files): + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2

C/C++:
Built as dynamic libs?: NO
C++ Compiler: /usr/lib/ccache/compilers/c++ (ver 4.8.2)
C++ flags (Release): -Wl,-strip-all -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wsign-promo -Wuninitialized -Winit-self -Wno-delete-non-virtual-dtor -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG
C++ flags (Debug): -Wl,-strip-all -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wsign-promo -Wuninitialized -Winit-self -Wno-delete-non-virtual-dtor -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG
C Compiler: /usr/lib/ccache/compilers/cc
C flags (Release): -Wl,-strip-all -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wuninitialized -Winit-self -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG
C flags (Debug): -Wl,-strip-all -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wuninitialized -Winit-self -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -msse -msse2 -msse3 -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG
Linker flags (Release): -L/root/ffmpeg_build/lib -Wl,--gc-sections
Linker flags (Debug): -L/root/ffmpeg_build/lib -Wl,--gc-sections
ccache: YES
Precompiled headers: NO
Extra dependencies: ade /opt/Qt4.8.7/lib/libQtGui.so /opt/Qt4.8.7/lib/libQtTest.so /opt/Qt4.8.7/lib/libQtCore.so /lib64/libz.so /opt/libjpeg-turbo/lib64/libjpeg.a dl m pthread rt
3rdparty dependencies: ittnotify libprotobuf libwebp libpng libtiff libjasper IlmImf quirc

OpenCV modules:
To be built: aruco bgsegm bioinspired calib3d ccalib core datasets dnn dnn_objdetect dpm face features2d flann fuzzy gapi hfs highgui img_hash imgcodecs imgproc line_descriptor ml objdetect optflow phase_unwrapping photo plot python3 quality reg rgbd saliency shape stereo stitching structured_light superres surface_matching text tracking video videoio videostab xfeatures2d ximgproc xobjdetect xphoto
Disabled: world
Disabled by dependency: -
Unavailable: cnn_3dobj cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev cvv freetype hdf java js matlab ovis python2 sfm ts viz
Applications: -
Documentation: NO
Non-free algorithms: NO

GUI:
QT: YES (ver 4.8.7 EDITION = OpenSource)
QT OpenGL support: NO
GTK+: NO
VTK support: NO

Media I/O:
ZLib: /lib64/libz.so (ver 1.2.3)
JPEG: /opt/libjpeg-turbo/lib64/libjpeg.a (ver 62)
WEBP: build (ver encoder: 0x020e)
PNG: build (ver 1.6.36)
TIFF: build (ver 42 - 4.0.10)
JPEG 2000: build (ver 1.900.1)
OpenEXR: build (ver 1.7.1)
HDR: YES
SUNRASTER: YES
PXM: YES
PFM: YES

Video I/O:
DC1394: NO
FFMPEG: YES
avcodec: YES (58.47.106)
avformat: YES (58.26.101)
avutil: YES (56.26.100)
swscale: YES (5.4.100)
avresample: NO
GStreamer: NO
v4l/v4l2: YES (linux/videodev2.h)

Parallel framework: pthreads

Trace: YES (with Intel ITT)

Other third-party libraries:
Lapack: NO
Eigen: NO
Custom HAL: NO
Protobuf: build (3.5.1)

OpenCL: YES (no extra features)
Include path: /io/opencv/3rdparty/include/opencl/1.2
Link libraries: Dynamic load

Python 3:
Interpreter: /opt/python/cp36-cp36m/bin/python (ver 3.6.8)
Libraries: libpython3.6m.a (ver 3.6.8)
numpy: /opt/python/cp36-cp36m/lib/python3.6/site-packages/numpy/core/include (ver 1.11.3)
install path: python

Python (for build): /opt/python/cp36-cp36m/bin/python

Java:
ant: NO
JNI: NO
Java wrappers: NO
Java tests: NO

Install to: /io/_skbuild/linux-x86_64-3.6/cmake-install
-----------------------------------------------------------------

Issue 2:
System information Raspberry PI 4 Centos7

OpenCV => 4.2

Operating System / Platform => Centos 7 / ARMV7L

Compiler => CMAKE3

Detailed description

In the installation process, after cloning openCV from official repository, I switched to branch 3.4, and ran CMAKE3, and it returned the following errors related to libraries, which I believe they are not available for AMRV7, Raspberry PI 4. Please see logs

Steps to reproduce

[@Rasp opencv]$ git checkout 3.4

Branch 3.4 set up to track remote branch 3.4 from origin.

Switched to a new branch '3.4'

[@Rasp opencv]$ mkdir build

[@Rasp opencv]$ cd build/

[o@Rasp build]$ cmake3 -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D OPENCV_GENERATE_PKGCONFIG=ON -D OPENCV_EXTRA_MODULES_PATH=/usr/local/src/opencv_build/opencv_contrib/modules -D BUILD_EXAMPLES=ON ..

-- The CXX compiler identification is GNU 4.8.5

-- The C compiler identification is GNU 4.8.5

-- Check for working CXX compiler: /usr/bin/c++

-- Check for working CXX compiler: /usr/bin/c++ - works

-- Detecting CXX compiler ABI info

-- Detecting CXX compiler ABI info - done

-- Detecting CXX compile features

-- Detecting CXX compile features - done

-- Check for working C compiler: /usr/bin/cc

-- Check for working C compiler: /usr/bin/cc - works

-- Detecting C compiler ABI info

-- Detecting C compiler ABI info - done

-- Detecting C compile features

-- Detecting C compile features - done

-- Detected processor: armv7l

-- Performing Test HAVE_CXX11 (check file: cmake/checks/cxx11.cpp)

-- Performing Test HAVE_CXX11 - Failed

-- Found PythonInterp: /usr/bin/python2.7 (found suitable version "2.7.5", minimum required is "2.7")

-- Found PythonLibs: /lib/libpython2.7.so (found suitable exact version "2.7.5")

-- Found PythonInterp: /usr/bin/python3 (found suitable version "3.6.8", minimum required is "3.2")

-- Could NOT find PythonLibs (missing: PYTHON_LIBRARIES PYTHON_INCLUDE_DIRS) (Required is exact version "3.6.8")

-- Looking for ccache - not found

-- Performing Test HAVE_CXX_FSIGNED_CHAR

-- Performing Test HAVE_CXX_FSIGNED_CHAR - Success

-- Performing Test HAVE_C_FSIGNED_CHAR

-- Performing Test HAVE_C_FSIGNED_CHAR - Success

-- Performing Test HAVE_CXX_W

-- Performing Test HAVE_CXX_W - Success

-- Performing Test HAVE_C_W

-- Performing Test HAVE_C_W - Success

-- Performing Test HAVE_CXX_WALL

-- Performing Test HAVE_CXX_WALL - Success

-- Performing Test HAVE_C_WALL

-- Performing Test HAVE_C_WALL - Success

-- Performing Test HAVE_CXX_WERROR_RETURN_TYPE

-- Performing Test HAVE_CXX_WERROR_RETURN_TYPE - Success

-- Performing Test HAVE_C_WERROR_RETURN_TYPE

-- Performing Test HAVE_C_WERROR_RETURN_TYPE - Success

-- Performing Test HAVE_CXX_WERROR_NON_VIRTUAL_DTOR

-- Performing Test HAVE_CXX_WERROR_NON_VIRTUAL_DTOR - Success

-- Performing Test HAVE_C_WERROR_NON_VIRTUAL_DTOR

-- Performing Test HAVE_C_WERROR_NON_VIRTUAL_DTOR - Success

-- Performing Test HAVE_CXX_WERROR_ADDRESS

-- Performing Test HAVE_CXX_WERROR_ADDRESS - Success

-- Performing Test HAVE_C_WERROR_ADDRESS

-- Performing Test HAVE_C_WERROR_ADDRESS - Success

-- Performing Test HAVE_CXX_WERROR_SEQUENCE_POINT

-- Performing Test HAVE_CXX_WERROR_SEQUENCE_POINT - Success

-- Performing Test HAVE_C_WERROR_SEQUENCE_POINT

-- Performing Test HAVE_C_WERROR_SEQUENCE_POINT - Success

-- Performing Test HAVE_CXX_WFORMAT

-- Performing Test HAVE_CXX_WFORMAT - Success

-- Performing Test HAVE_C_WFORMAT

-- Performing Test HAVE_C_WFORMAT - Success

-- Performing Test HAVE_CXX_WERROR_FORMAT_SECURITY

-- Performing Test HAVE_CXX_WERROR_FORMAT_SECURITY - Success

-- Performing Test HAVE_C_WERROR_FORMAT_SECURITY

-- Performing Test HAVE_C_WERROR_FORMAT_SECURITY - Success

-- Performing Test HAVE_CXX_WMISSING_DECLARATIONS

-- Performing Test HAVE_CXX_WMISSING_DECLARATIONS - Success

-- Performing Test HAVE_C_WMISSING_DECLARATIONS

-- Performing Test HAVE_C_WMISSING_DECLARATIONS - Success

-- Performing Test HAVE_CXX_WMISSING_PROTOTYPES

-- Performing Test HAVE_CXX_WMISSING_PROTOTYPES - Failed

-- Performing Test HAVE_C_WMISSING_PROTOTYPES

-- Performing Test HAVE_C_WMISSING_PROTOTYPES - Success

-- Performing Test HAVE_CXX_WSTRICT_PROTOTYPES

-- Performing Test HAVE_CXX_WSTRICT_PROTOTYPES - Failed

-- Performing Test HAVE_C_WSTRICT_PROTOTYPES

-- Performing Test HAVE_C_WSTRICT_PROTOTYPES - Success

-- Performing Test HAVE_CXX_WUNDEF

-- Performing Test HAVE_CXX_WUNDEF - Success

-- Performing Test HAVE_C_WUNDEF

-- Performing Test HAVE_C_WUNDEF - Success

-- Performing Test HAVE_CXX_WINIT_SELF

-- Performing Test HAVE_CXX_WINIT_SELF - Success

-- Performing Test HAVE_C_WINIT_SELF

-- Performing Test HAVE_C_WINIT_SELF - Success

-- Performing Test HAVE_CXX_WPOINTER_ARITH

-- Performing Test HAVE_CXX_WPOINTER_ARITH - Success

-- Performing Test HAVE_C_WPOINTER_ARITH

-- Performing Test HAVE_C_WPOINTER_ARITH - Success

-- Performing Test HAVE_CXX_WSHADOW

-- Performing Test HAVE_CXX_WSHADOW - Success

-- Performing Test HAVE_C_WSHADOW

-- Performing Test HAVE_C_WSHADOW - Success

-- Performing Test HAVE_CXX_WSIGN_PROMO

-- Performing Test HAVE_CXX_WSIGN_PROMO - Success

-- Performing Test HAVE_C_WSIGN_PROMO

-- Performing Test HAVE_C_WSIGN_PROMO - Failed

-- Performing Test HAVE_CXX_WUNINITIALIZED

-- Performing Test HAVE_CXX_WUNINITIALIZED - Success

-- Performing Test HAVE_C_WUNINITIALIZED

-- Performing Test HAVE_C_WUNINITIALIZED - Success

-- Performing Test HAVE_CXX_WNO_DELETE_NON_VIRTUAL_DTOR

-- Performing Test HAVE_CXX_WNO_DELETE_NON_VIRTUAL_DTOR - Success

-- Performing Test HAVE_C_WNO_DELETE_NON_VIRTUAL_DTOR

-- Performing Test HAVE_C_WNO_DELETE_NON_VIRTUAL_DTOR - Failed

-- Performing Test HAVE_CXX_WNO_UNNAMED_TYPE_TEMPLATE_ARGS

-- Performing Test HAVE_CXX_WNO_UNNAMED_TYPE_TEMPLATE_ARGS - Failed

-- Performing Test HAVE_C_WNO_UNNAMED_TYPE_TEMPLATE_ARGS

-- Performing Test HAVE_C_WNO_UNNAMED_TYPE_TEMPLATE_ARGS - Failed

-- Performing Test HAVE_CXX_WNO_COMMENT

-- Performing Test HAVE_CXX_WNO_COMMENT - Success

-- Performing Test HAVE_C_WNO_COMMENT

-- Performing Test HAVE_C_WNO_COMMENT - Success

-- Performing Test HAVE_CXX_WNO_MISSING_FIELD_INITIALIZERS

-- Performing Test HAVE_CXX_WNO_MISSING_FIELD_INITIALIZERS - Success

-- Performing Test HAVE_C_WNO_MISSING_FIELD_INITIALIZERS

-- Performing Test HAVE_C_WNO_MISSING_FIELD_INITIALIZERS - Success

-- Performing Test HAVE_CXX_FDIAGNOSTICS_SHOW_OPTION

-- Performing Test HAVE_CXX_FDIAGNOSTICS_SHOW_OPTION - Success

-- Performing Test HAVE_C_FDIAGNOSTICS_SHOW_OPTION

-- Performing Test HAVE_C_FDIAGNOSTICS_SHOW_OPTION - Success

-- Performing Test HAVE_CXX_PTHREAD

-- Performing Test HAVE_CXX_PTHREAD - Success

-- Performing Test HAVE_C_PTHREAD

-- Performing Test HAVE_C_PTHREAD - Success

-- Performing Test HAVE_CXX_FOMIT_FRAME_POINTER

-- Performing Test HAVE_CXX_FOMIT_FRAME_POINTER - Success

-- Performing Test HAVE_C_FOMIT_FRAME_POINTER

-- Performing Test HAVE_C_FOMIT_FRAME_POINTER - Success

-- Performing Test HAVE_CXX_FFUNCTION_SECTIONS

-- Performing Test HAVE_CXX_FFUNCTION_SECTIONS - Success

-- Performing Test HAVE_C_FFUNCTION_SECTIONS

-- Performing Test HAVE_C_FFUNCTION_SECTIONS - Success

-- Performing Test HAVE_CXX_FDATA_SECTIONS

-- Performing Test HAVE_CXX_FDATA_SECTIONS - Success

-- Performing Test HAVE_C_FDATA_SECTIONS

-- Performing Test HAVE_C_FDATA_SECTIONS - Success

-- Performing Test HAVE_CXX_MFPU_VFPV3

-- Performing Test HAVE_CXX_MFPU_VFPV3 - Success

-- Performing Test HAVE_CPU_NEON_SUPPORT (check file: cmake/checks/cpu_neon.cpp)

-- Performing Test HAVE_CPU_NEON_SUPPORT - Failed

-- Performing Test HAVE_CXX_MFPU_NEON (check file: cmake/checks/cpu_neon.cpp)

-- Performing Test HAVE_CXX_MFPU_NEON - Success

-- Performing Test HAVE_CPU_FP16_SUPPORT (check file: cmake/checks/cpu_fp16.cpp)

-- Performing Test HAVE_CPU_FP16_SUPPORT - Failed

-- Performing Test HAVE_CXX_MFPU_NEON_FP16_MFP16_FORMAT_IEEE (check file: cmake/checks/cpu_fp16.cpp)

-- Performing Test HAVE_CXX_MFPU_NEON_FP16_MFP16_FORMAT_IEEE - Failed

-- FP16 is not supported by C++ compiler

-- Performing Test HAVE_CPU_BASELINE_FLAGS

-- Performing Test HAVE_CPU_BASELINE_FLAGS - Success

-- Performing Test HAVE_CXX_FVISIBILITY_HIDDEN

-- Performing Test HAVE_CXX_FVISIBILITY_HIDDEN - Success

-- Performing Test HAVE_C_FVISIBILITY_HIDDEN

-- Performing Test HAVE_C_FVISIBILITY_HIDDEN - Success

-- Performing Test HAVE_CXX_FVISIBILITY_INLINES_HIDDEN

-- Performing Test HAVE_CXX_FVISIBILITY_INLINES_HIDDEN - Success

-- Performing Test HAVE_C_FVISIBILITY_INLINES_HIDDEN

-- Performing Test HAVE_C_FVISIBILITY_INLINES_HIDDEN - Failed

-- Performing Test HAVE_LINK_AS_NEEDED

-- Performing Test HAVE_LINK_AS_NEEDED - Success

-- Looking for pthread.h

-- Looking for pthread.h - found

-- Looking for posix_memalign

-- Looking for posix_memalign - found

-- Looking for malloc.h

-- Looking for malloc.h - found

-- Looking for memalign

-- Looking for memalign - found

-- Check if the system is big endian

-- Searching 16 bit integer

-- Looking for sys/types.h

-- Looking for sys/types.h - found

-- Looking for stdint.h

-- Looking for stdint.h - found

-- Looking for stddef.h

-- Looking for stddef.h - found

-- Check size of unsigned short

-- Check size of unsigned short - done

-- Searching 16 bit integer - Using unsigned short

-- Check if the system is big endian - little endian

-- Found ZLIB: /lib/libz.so (found suitable version "1.2.7", minimum required is "1.2.3")

-- Found JPEG: /lib/libjpeg.so (found version "62")

-- Found TIFF: /lib/libtiff.so (found version "4.0.3")

-- Found WebP: /lib/libwebp.so

-- Found Jasper: /lib/libjasper.so (found version "1.900.1")

-- Found ZLIB: /lib/libz.so (found version "1.2.7")

-- Found PNG: /lib/libpng.so (found version "1.5.13")

-- Looking for /usr/include/libpng/png.h

-- Looking for /usr/include/libpng/png.h - not found

-- Found OpenEXR: /usr/lib/libIlmImf.so

-- Checking for module 'gtk+-3.0'

-- No package 'gtk+-3.0' found

-- Checking for module 'gtk+-2.0'

-- Found gtk+-2.0, version 2.24.31

-- Checking for module 'gthread-2.0'

-- Found gthread-2.0, version 2.56.1

-- Checking for modules 'gstreamer-base-1.0;gstreamer-video-1.0;gstreamer-app-1.0;gstreamer-riff-1.0;gstreamer-pbutils-1.0'

-- No package 'gstreamer-base-1.0' found

-- No package 'gstreamer-video-1.0' found

-- No package 'gstreamer-app-1.0' found

-- No package 'gstreamer-riff-1.0' found

-- No package 'gstreamer-pbutils-1.0' found

-- Checking for modules 'gstreamer-base-0.10;gstreamer-video-0.10;gstreamer-app-0.10;gstreamer-riff-0.10;gstreamer-pbutils-0.10'

-- Found gstreamer-base-0.10, version 0.10.36

-- Found gstreamer-video-0.10, version 0.10.36

-- Found gstreamer-app-0.10, version 0.10.36

-- Found gstreamer-riff-0.10, version 0.10.36

-- Found gstreamer-pbutils-0.10, version 0.10.36

-- Checking for module 'libdc1394-2'

-- Found libdc1394-2, version 2.2.2

-- Looking for linux/videodev.h

-- Looking for linux/videodev.h - not found

-- Looking for linux/videodev2.h

-- Looking for linux/videodev2.h - found

-- Looking for sys/videoio.h

-- Looking for sys/videoio.h - not found

-- Checking for modules 'libavcodec;libavformat;libavutil;libswscale'

-- No package 'libavcodec' found

-- No package 'libavformat' found

-- No package 'libavutil' found

-- No package 'libswscale' found

-- Checking for module 'libavresample'

-- No package 'libavresample' found

-- Could not find OpenBLAS include. Turning OpenBLAS_FOUND off

-- Could not find OpenBLAS lib. Turning OpenBLAS_FOUND off

-- Could NOT find Atlas (missing: Atlas_CBLAS_INCLUDE_DIR Atlas_CLAPACK_INCLUDE_DIR Atlas_CBLAS_LIBRARY Atlas_BLAS_LIBRARY Atlas_LAPACK_LIBRARY)

-- Looking for sgemm_

-- Looking for sgemm_ - not found

-- Looking for pthread.h

-- Looking for pthread.h - found

-- Performing Test CMAKE_HAVE_LIBC_PTHREAD

-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success

-- Found Threads: TRUE

-- Could NOT find BLAS (missing: BLAS_LIBRARIES)

-- LAPACK requires BLAS

-- A library with LAPACK API not found. Please specify library location.

-- Performing Test HAVE_CXX_WNO_DEPRECATED

-- Performing Test HAVE_CXX_WNO_DEPRECATED - Success

-- Performing Test HAVE_CXX_WNO_MISSING_PROTOTYPES

-- Performing Test HAVE_CXX_WNO_MISSING_PROTOTYPES - Failed

-- Performing Test HAVE_CXX_WNO_MISSING_DECLARATIONS

-- Performing Test HAVE_CXX_WNO_MISSING_DECLARATIONS - Success

-- Performing Test HAVE_CXX_WNO_SHADOW

-- Performing Test HAVE_CXX_WNO_SHADOW - Success

-- Performing Test HAVE_CXX_WNO_UNUSED_PARAMETER

-- Performing Test HAVE_CXX_WNO_UNUSED_PARAMETER - Success

-- Performing Test HAVE_CXX_WNO_UNUSED_LOCAL_TYPEDEFS

-- Performing Test HAVE_CXX_WNO_UNUSED_LOCAL_TYPEDEFS - Success

-- Performing Test HAVE_CXX_WNO_SIGN_COMPARE

-- Performing Test HAVE_CXX_WNO_SIGN_COMPARE - Success

-- Performing Test HAVE_CXX_WNO_SIGN_PROMO

-- Performing Test HAVE_CXX_WNO_SIGN_PROMO - Success

-- Performing Test HAVE_CXX_WNO_UNDEF

-- Performing Test HAVE_CXX_WNO_UNDEF - Success

-- Performing Test HAVE_CXX_WNO_TAUTOLOGICAL_UNDEFINED_COMPARE

-- Performing Test HAVE_CXX_WNO_TAUTOLOGICAL_UNDEFINED_COMPARE - Failed

-- Performing Test HAVE_CXX_WNO_IGNORED_QUALIFIERS

-- Performing Test HAVE_CXX_WNO_IGNORED_QUALIFIERS - Success

-- Performing Test HAVE_CXX_WNO_EXTRA

-- Performing Test HAVE_CXX_WNO_EXTRA - Success

-- Performing Test HAVE_CXX_WNO_UNUSED_FUNCTION

-- Performing Test HAVE_CXX_WNO_UNUSED_FUNCTION - Success

-- Performing Test HAVE_CXX_WNO_UNUSED_CONST_VARIABLE

-- Performing Test HAVE_CXX_WNO_UNUSED_CONST_VARIABLE - Failed

-- Performing Test HAVE_CXX_WNO_SHORTEN_64_TO_32

-- Performing Test HAVE_CXX_WNO_SHORTEN_64_TO_32 - Failed

-- Performing Test HAVE_CXX_WNO_INVALID_OFFSETOF

-- Performing Test HAVE_CXX_WNO_INVALID_OFFSETOF - Success

-- Performing Test HAVE_CXX_WNO_ENUM_COMPARE_SWITCH

-- Performing Test HAVE_CXX_WNO_ENUM_COMPARE_SWITCH - Failed

-- Performing Test HAVE_CXX_WNO_SUGGEST_OVERRIDE

-- Performing Test HAVE_CXX_WNO_SUGGEST_OVERRIDE - Failed

-- Performing Test HAVE_CXX_WNO_INCONSISTENT_MISSING_OVERRIDE

-- Performing Test HAVE_CXX_WNO_INCONSISTENT_MISSING_OVERRIDE - Failed

-- Performing Test HAVE_CXX_WNO_IMPLICIT_FALLTHROUGH

-- Performing Test HAVE_CXX_WNO_IMPLICIT_FALLTHROUGH - Failed

-- Performing Test HAVE_CXX_WNO_ARRAY_BOUNDS

-- Performing Test HAVE_CXX_WNO_ARRAY_BOUNDS - Success

-- Could NOT find JNI (missing: JAVA_AWT_LIBRARY JAVA_JVM_LIBRARY JAVA_INCLUDE_PATH JAVA_INCLUDE_PATH2 JAVA_AWT_INCLUDE_PATH)

-- Could NOT find Pylint (missing: PYLINT_EXECUTABLE)

-- Could NOT find Flake8 (missing: FLAKE8_EXECUTABLE)

-- VTK is not found. Please set -DVTK_DIR in CMake to VTK build directory, or to VTK install subdirectory with VTKConfig.cmake file

-- Performing Test HAVE_C_WNO_UNUSED_VARIABLE

-- Performing Test HAVE_C_WNO_UNUSED_VARIABLE - Success

-- Performing Test HAVE_C_WNO_SHADOW

-- Performing Test HAVE_C_WNO_SHADOW - Success

-- Carotene: NEON is not available, disabling carotene...

-- Looking for dlerror in dl

-- Looking for dlerror in dl - found

-- Performing Test HAVE_C_WNO_IMPLICIT_FALLTHROUGH

-- Performing Test HAVE_C_WNO_IMPLICIT_FALLTHROUGH - Failed

-- Performing Test HAVE_C_WNO_UNDEF

-- Performing Test HAVE_C_WNO_UNDEF - Success

-- Performing Test HAVE_C_WNO_SIGN_COMPARE

-- Performing Test HAVE_C_WNO_SIGN_COMPARE - Success

calib3d

core

cudaarithm

cudabgsegm

cudacodec

cudafeatures2d

cudafilters

cudaimgproc

cudalegacy

cudaobjdetect

cudaoptflow

cudastereo

cudawarping

cudev

dnn

features2d

flann

highgui

imgcodecs

imgproc

java

js

ml

objdetect

photo

python

shape

stitching

superres

ts

video

videoio

videostab

viz

world

alphamat

aruco

bgsegm

bioinspired

ccalib

cnn_3dobj

cudaarithm

cudabgsegm

cudacodec

cudafeatures2d

cudafilters

cudaimgproc

cudalegacy

cudaobjdetect

cudaoptflow

cudastereo

cudawarping

cudev

cvv

datasets

dnn_objdetect

dnn_superres

dpm

face

freetype

fuzzy

hdf

hfs

img_hash

intensity_transform

julia

line_descriptor

matlab

mcc

optflow

ovis

phase_unwrapping

plot

quality

rapid

reg

rgbd

saliency

sfm

shape

stereo

structured_light

superres

surface_matching

text

tracking

videostab

viz

xfeatures2d

ximgproc

xobjdetect

xphoto

CMake Error at cmake/OpenCVModule.cmake:353 (message):

Duplicated modules NAMES has been found

Call Stack (most recent call first):

cmake/OpenCVModule.cmake:371 (_assert_uniqueness)

modules/CMakeLists.txt:7 (ocv_glob_modules)

-- Configuring incomplete, errors occurred!

See also "/usr/local/src/opencv_build/opencv/build/CMakeFiles/CMakeOutput.log".

See also "/usr/local/src/opencv_build/opencv/build/CMakeFiles/CMakeError.log".