Tbb/tbb_stddef.h cannot find this header

[berak]

are you sure you have those headers installed ?

sudo apt install libtbb-dev

should do it

try, delete build/CMakeCache.txt (!!!) & re-run cmake
then, carefully look at the output (& show us !), it should have messages about it

@OliviaWang

and manually put the path in the cmake/OpenCVDetectTBB.cmake file,

no, do not mess with that