How to link ICU4C in cmake via pkg-config on MacOS? [duplicate] - cmake

Question

This question already has answers here:
Cmake cannot find library using "link_directories"
(4 answers)
Closed 3 years ago.
I work on macbook with newest OS. Installed icu4c library via homebrew. But I cannot link libicuuc correctly. In case of find library, I use
export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/Cellar/icu4c/64.2/lib/pkgconfig
on my ~/.bashrc, but still got link error.
This is a very simple CMakeLists.txt:
cmake_minimum_required(VERSION 3.4)
project(xeditd CXX)
find_package(PkgConfig REQUIRED)
pkg_search_module(ICU_UC icu-uc)
set(LIB_DIR
${ICU_UC_LIBRARY_DIRS}
)
set(LIB
${ICU_UC_LIBRARIES}
)
set(INC_DIR
${ICU_UC_INCLUDE_DIRS}
)
set(SRC_FILE
xeditd.cpp
)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -o2 ${ICU_UC_CXXFLAGS_OTHER}")
message(${LIB_DIR})
message(${LIB})
message(${INC_DIR})
message(${CMAKE_CXX_FLAGS})
add_executable(xeditd ${SRC_FILE})
link_directories(${LIB_DIR})
target_link_libraries(xeditd ${LIB})
target_include_directories(xeditd PUBLIC ${INC_DIR})
It generate:
/usr/local/Cellar/icu4c/64.2/lib (${LIB_DIR})
icuucicudata (${LIB})
/usr/local/Cellar/icu4c/64.2/include (${INC_DIR})
-std=c++14 -std=c++14 -o2 (${CMAKE_CXX_FLAGS})
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/rolin/workspace/github/xedit/.bin
[ 50%] Linking CXX executable xedit
ld: library not found for -licuuc
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [xedit/xedit] Error 1
make[1]: *** [xedit/CMakeFiles/xedit.dir/all] Error 2
make: *** [all] Error 2
[ 50%] Linking CXX executable xeditd
ld: library not found for -licuuc
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [xeditd/xeditd] Error 1
make[1]: *** [xeditd/CMakeFiles/xeditd.dir/all] Error 2
make: *** [all] Error 2
I don't known why libicuuc.dylib not found.

Answer 1

link_directories only affects targets that come AFTER it. So I move add_executable after the link_directories call.