[SOLVED] CMake: IMPORTED_LOCATION not set for imported target

Issue

I'm cross-compiling a Linux library for ARM using dockcross and linking to OpenCV. OpenCV builds and installs successfully, but configuring my library gives me errors like this:

CMake Error in build/_deps/mylib-src/CMakeLists.txt:
  IMPORTED_LOCATION not set for imported target "opencv_core" configuration
  "Release".

I'm finding the OpenCV package like this:

find_package( OpenCV REQUIRED )

And linking like this:

target_link_libraries( ${PROJECT_NAME} ${OpenCV_LIBS})

I didn't find the documentation for IMPORTED_LOCATION very helpful. What does this error mean, and how do I fix it?

Solution

This worked:

set_target_properties(opencv_core PROPERTIES IMPORTED_LOCATION ${CMAKE_SYSROOT}/usr/local/lib/libopencv_core.so)

But I still don't know why I needed it...

Answered By - TS_

Answer Checked By - Senaida (WPSolving Volunteer)