No rule to make target makefile when using an external library - c++11

Question

I have attempted to troubleshoot this issue, but eventually I gave up and I cannot figure it out.
I am using CLion and I need to import an external shared library (ts3client.so). Whatever I do, it fails in one way or another.
Currently, I have the following:
cmake_minimum_required(VERSION 3.8)
project(TSMusicBot)
set(CMAKE_CXX_STANDARD 11)
set(SOURCE_FILES src/main.cpp)
# Teamspeak Libraries
INCLUDE_DIRECTORIES(libs/ts3_sdk_3.0.4/include)
ADD_LIBRARY (libts3client SHARED IMPORTED GLOBAL)
SET_PROPERTY (
TARGET libts3client PROPERTY IMPORTED_LOCATION
libs/ts3_sdk_3.0.4/bin/linux/amd64/libts3client.so)
add_executable(TSMusicBot ${SOURCE_FILES})
target_link_libraries(TSMusicBot libts3client)
This gives me the following error:
make[2]: *** No rule to make target 'libs/ts3_sdk_3.0.4/bin/linux/amd64/libts3client.so', needed by 'TSMusicBot'. Stop.
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/TSMusicBot.dir/all' failed
make[1]: *** [CMakeFiles/TSMusicBot.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
My directory structure is the following:
src/main.cpp (the code)
libs/ts3_sdk_3.0.4/include/teamspeak/ (which contains headers for the library)
libs/ts3_sdk_3.0.4/bin/linux/amd64/libts3client.so (which is the library I cannot import).

Answer 1

The problem is here:
SET_PROPERTY (
TARGET libts3client PROPERTY IMPORTED_LOCATION
libs/ts3_sdk_3.0.4/bin/linux/amd64/libts3client.so)
You have a plain relative path there, which often will cause problems with CMake because it will run your commands in different directories than the one where CMakeLists.txt exists.
As we discovered in a comment, changing the IMPORTED_LOCATION to an absolute path fixes it. However, the proper solution is to use a relative path with a known base:
SET_PROPERTY (
TARGET libts3client PROPERTY IMPORTED_LOCATION
${CMAKE_CURRENT_SOURCE_DIR}/libs/ts3_sdk_3.0.4/bin/linux/amd64/libts3client.so)
This says explicitly that the libs directory is under the directory where this CMakeLists.txt file is.