Version 11.00 added multi-threading support, but we need to link to -lpthread
to resolve symbols.

--- CMakeLists.txt.orig	2026-06-28 11:27:58 UTC
+++ CMakeLists.txt
@@ -18,6 +18,8 @@ endif()
   add_compile_options(-Wpedantic)
 endif()
 
+find_package(Threads)
+
 #
 # Determine interface version
 #
@@ -244,6 +246,7 @@ if(BUILD_SHARED)
 if(BUILD_SHARED)
     add_library(MAC SHARED $<TARGET_OBJECTS:shared> $<TARGET_OBJECTS:objects>)
     set_target_properties(MAC PROPERTIES VERSION ${MAC_SOVERSION} SOVERSION ${MAC_SOVERSION})
+    target_link_libraries(MAC Threads::Threads)
 
     if(WIN32)
         if(${ARCHITECTURE} STREQUAL x86)
@@ -330,7 +333,7 @@ if(BUILD_UTIL)
        Source/Console/Console.cpp)
 
     add_executable(macutil ${MAC_UTIL_HEADER_FILES} ${MAC_UTIL_SOURCE_FILES} $<TARGET_OBJECTS:shared>)
-    target_link_libraries(macutil MAC)
+    target_link_libraries(macutil MAC Threads::Threads)
 
     target_include_directories(macutil PUBLIC
        ${CMAKE_CURRENT_SOURCE_DIR}/Source/MACLib
