Fix building FFI on Linux

ffi/examples/CMakeLists.txt

@@ -12,6 +12,8 @@ set(EXAMPLES_DIR ${CMAKE_SOURCE_DIR}/../examples)
 # Find all C example files
 file(GLOB EXAMPLE_SOURCES ${EXAMPLES_DIR}/*.c)
 
+find_package(PkgConfig REQUIRED)
+
 # Create an executable for each example file
 foreach(EXAMPLE_FILE ${EXAMPLE_SOURCES})
     # Extract the filename without the path
@@ -26,6 +28,11 @@ foreach(EXAMPLE_FILE ${EXAMPLE_SOURCES})
     # Link the static Rust library
     target_link_libraries(${EXAMPLE_NAME} PRIVATE ${STATIC_LIB})
 
+    if(UNIX AND NOT APPLE)
+      target_link_libraries(${EXAMPLE_NAME} PRIVATE m)
+    endif()
+
+
     # libplist
 
     if( APPLE )

ffi/examples/heartbeat.c

@@ -5,7 +5,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/_types/_u_int64_t.h>
 
 int main() {
   // Initialize logger