I have a c++ project that uses the OpenCV library. It takes a long time to build when I run make. How can I speed up the build time?

I did install OpenCV with GPU support and thought this might be the bottleneck (since it may be compiling for different GPU architectures?), so I tried using cmake -D WITH_CUDA=OFF .. to build my project. Unfortunately, this didn't do the trick... Any tips?

Note: I'm fine disabling the GPU if it speeds up compile time significantly.

This is what my CMakeLists.txt file looks like:

cmake_minimum_required(VERSION 3.10)
project(Cruisin VERSION 1.0)
find_package( OpenCV REQUIRED)
find_package (Threads)

include_directories(include)
include_directories( ${OpenCV_INCLUDE_DIRS} )

file(GLOB SOURCES src/*.cpp app/main.cpp)

add_executable(main ${SOURCES})
target_link_libraries( main ${CMAKE_THREAD_LIBS_INIT} ) # Add threading lib
target_link_libraries( main ${OpenCV_LIBS} )

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)

Other Details:

• Compiler: gcc

• OS: virtual Ubuntu 20.04 (WSL2 on Windows 10)

• Project structure: there's one main cpp file in ROOT/app/, 2 source files in ROOT/src/ with 2 corresponding headers in ROOT/include/

• OpenCV and my project files are located on the regular Windows file system (accessed through /mnt/ directory), but CUDA and Make/CMake are in the virtual WSL

Edit: Solution

The issue seemed to be WSL being very slow with any I/O being done in the windows filesystem. In my case, I was using OpenCV installed somewhere in mnt/ (Windows filesystem). I rebuilt OpenCV in WSL somewhere in /, and moved my project there as well and it is so much faster.