Apple Mach-O Linker error with Allegro5 and Xcode with CMake - c++

Question

I'm trying to set up a project project in Xcode with allegro. I installed allegro5 using homebrew. My CMakeLists.txt is as below:
set(SOURCE_FILES "main.cpp")
add_executable(core ${SOURCE_FILES})
if(WIN32)
# TODO.
else(APPLE)
set(ALLEGRO_INCLUDE "/usr/local/include")
set(ALLEGRO_LIB "/usr/local/lib")
set(ALLEGRO_DYLIB, "/usr/local/lib/*.dylib")
set(ALLEGRO_LINK_FLAGS "-lallegro -lallegro_main")
endif()
include_directories(${ALLEGRO_INCLUDE})
link_directories(${ALLEGRO_LIB})
file(GLOB LIBRARIES ${ALLEGRO_DYLIB})
target_link_libraries(core ${LIBRARIES} ${ALLEGRO_LINK_FLAGS})
However, I keep getting the error: ld: library not found for -lallegro
EDIT:
Edited CMakeLists.txt file:
set(SOURCE_FILES "main.cpp")
add_executable(core ${SOURCE_FILES})
if(WIN32)
# TODO.
else(APPLE)
set(ALLEGRO_INCLUDE "/usr/local/include")
set(ALLEGRO_LIB "/usr/local/lib")
set(ALLEGRO_DYLIB, "/usr/local/lib/*.dylib")
endif()
include_directories(${ALLEGRO_INCLUDE})
link_directories(${ALLEGRO_LIB})
file(GLOB LIBRARIES ${ALLEGRO_DYLIB})
target_link_libraries(core ${LIBRARIES} ${ALLEGRO_DYLIB})
And now I'm getting the error:
Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
(maybe you meant: __al_mangled_main)
ld: symbol(s) not found for architecture x86_64

Answer 1

You misunderstood target_link_libraries, you don't set the link flags here, but you indicate the list of libraries you want to target, so that would be:
target_link_libraries(core ${LIBRARIES} ${ALLEGRO_DYLIB})
Otherwise you will get flags like -l-lallegro.