More Apple attempts.

CMakeLists.txt

@@ -5,7 +5,8 @@ cmake_minimum_required(VERSION 3.14.1)
 if(APPLE)
   project(C5T LANGUAGES C CXX OBJC)
   message(STATUS "We are on 'Darwin'!")
-  #set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -x objective-c++")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -x objective-c++")
+  find_library(FOUNDATION_LIBRARY Foundation)
 elseif(UNIX)
   project(C5T LANGUAGES C CXX)
   message(STATUS "We are on Unix!")
@@ -45,7 +46,11 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     add_executable(${TEST_NAME} "${TEST_SOURCE_FULL_NAME_CC}") 
     target_compile_definitions(${TEST_NAME} PRIVATE CURRENT_CMAKE_BUILT_TEST)
     target_include_directories(${TEST_NAME} PRIVATE "${CMAKE_SOURCE_DIR}/scripts")  # For `current_build.h`, needed for `karl/`.
-    target_link_libraries(${TEST_NAME} PRIVATE Threads::Threads dl C5T)
+    if(APPLE)
+      target_link_libraries(${TEST_NAME} PRIVATE Threads::Threads dl ${FOUNDATION_LIBRARY})
+    else()
+      target_link_libraries(${TEST_NAME} PRIVATE Threads::Threads dl)
+    endif()
     add_test(${TEST_NAME} ${TEST_NAME} COMMAND ${TEST_NAME})
   endforeach()
 endif()