Opencv build fails rpi4

Question

I am trying to build opencv as directed for python3.7, on pi4 (2Gb Ram) with Raspbian Buster Lite, everything goes fine until I try

make -j -l 2

After 57% progress I get following error

[ 57%] Linking CXX shared library ../../lib/libopencv_core.so
/usr/bin/ld: ../../3rdparty/ippicv/ippicv_lnx/icv/lib/ia32/libippicv.a(ippcpufeatures.o): relocations in generic ELF (EM: 3)
/usr/bin/ld: ../../3rdparty/ippicv/ippicv_lnx/icv/lib/ia32/libippicv.a: error adding symbols: file in wrong format
collect2: error: ld returned 1 exit status
make[2]: *** [modules/core/CMakeFiles/opencv_core.dir/build.make:1347: lib/libopencv_core.so.4.1.1] Error 1
make[1]: *** [CMakeFiles/Makefile2:1371: modules/core/CMakeFiles/opencv_core.dir/all] Error 2

I have tried

• installing and removing python3-opencv library
• opencv version 4.1.1 and 3.4.5

in both scenarios error remains same.

Answer 1

Try running just make, as it's possible the Pi doesn't have enough memory to run the build on two cores. It takes longer, but it worked for me.