Executable built using cmake cannot find shared library - visual-studio

Question

I have been working on a Visual Studio 2019 project with the objective of porting the application to Centos 8. I'm using a CMake project in VS2019 with remote building on my Centos machine. Basically, all the files are transferred to the remote machine and the project is built. My project directory looks as
Child
| CMakeLists.txt
| source
|__public
| headers
| libs
Parent
| CMakeLists.txt
| source
Child generates a shared library (.so) and some public headers which are to be linked in Parent. The so files and public headers are present in the public directory of Child. The CMake files of both the files are as follows
Child/CMakeLists.txt
set(PROJECT_NAME "Child")
set(Header_Files
#set of public headers and source headers
)
set(Source_Files
#set of source files
)
set(ALL_FILES
${Header_Files}
${Source_Files}
)
if (UNIX)
#Target is an SO
add_library(${PROJECT_NAME} SHARED ${ALL_FILES})
set(BOOST_INCLUDEDIR "${CMAKE_HOME_DIRECTORY}/Boost")
set(BOOST_LIBRARYDIR "${CMAKE_HOME_DIRECTORY}/Boost/libs/linux64-clang-9.0.0/static/release")
find_package(Boost REQUIRED)
if (Boost_FOUND)
target_include_directories(${PROJECT_NAME} PRIVATE ${Boost_INCLUDE_DIRS})
target_link_libraries(${PROJECT_NAME} ${Boost_LIBRARIES})
endif()
set(XercesC_INCLUDE_DIR "${CMAKE_HOME_DIRECTORY}/Xercesc/Linux-Clang-Release/include")
set(XercesC_LIBRARY "${CMAKE_HOME_DIRECTORY}/Xercesc/Linux-Clang-Release/lib64")
find_package(XercesC REQUIRED)
if (XercesC_FOUND)
target_include_directories(${PROJECT_NAME} PRIVATE ${XercesC_INCLUDE_DIR})
target_link_libraries(${PROJECT_NAME} "${CMAKE_HOME_DIRECTORY}/Xercesc/Linux-Clang-Release/lib64/libxerces-c.so")
endif()
endif()
Parent/CMakeLists.txt
set(PROJECT_NAME "Parent")
set(Header_Files
#set of headers
)
set(Source_Files
#set of source files
)
set(ALL_FILES
${Header_Files}
${Source_Files}
)
if (UNIX)
set(CHILD_HEADERS "${CMAKE_HOME_DIRECTORY}/Child/public/headers")
set(CHILD_LIB_DIR "${CMAKE_BINARY_DIR}/Child/libs")
link_directories(${CHILD_LIB_DIR})
add_executable(${PROJECT_NAME} ${ALL_FILES})
target_include_directories(${PROJECT_NAME} PRIVATE ${CHILD_HEADERS})
target_link_libraries(${PROJECT_NAME} PRIVATE Child)
#Copy libChild.so to Parent executable directory
add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD COMMAND
cp "${CHILD_LIB_DIR}/libChild.so"
"${CMAKE_CURRENT_BINARY_DIR}/libChild.so"
)
endif()
Problem
My objective is to have a build for my customer. Hence, I need to package all the executables and libs under a single zip folder. However, upon doing so I find the linker paths to have taken absolute path values of the sort
$ldd Parent
libChild.so => /root/.vs/Project/829a6827-2641-4552-a2fb-abec91ed47a2/out/build/Linux-Clang-Release/Child/libChild.so (0x00007f6934908000)
However, concerning my final build folder will be like this
Parent (executable)
libChild.so
libboost_regex...
libxerces... etc. etc.
I kinda want a relative path link to the same directory
libChild.so => ./libChild.so
Thus, when I export as a zip to another machine, it is unable to find the shared library. I have tried a couple of things (using other CMake functions) as well as copying the library into the executable directory first and then linking. However, it still links it as an absolute path which is likely to cause the same issue again. I have gone through the CMake documentation and perused through cmake-packages and relocatable packages but unable to fix the problem.

Answer 1

The issue can be resolved by placing these two statements in the CMake files for Project Child and Project Parent.
set(CMAKE_INSTALL_RPATH ".")
set(CMAKE_BUILD_WITH_INSTALL_RPATH true)
Details about what these variables mean can be found in the CMake documentation.
Although this resolves the issue at the moment, however, this is not the correct approach for creating builds for a customer, as pointed out here.