add the atomic lib

CMakeLists.txt

@@ -256,6 +256,12 @@ ELSE()
     ADD_EXECUTABLE(umskt src/main.cpp src/cli.cpp ${UMSKT_EXE_WINDOWS_EXTRA})
     TARGET_INCLUDE_DIRECTORIES(umskt PUBLIC ${OPENSSL_INCLUDE_DIR})
     TARGET_LINK_LIBRARIES(umskt _umskt ${OPENSSL_CRYPTO_LIBRARIES} ${ZLIB_LIBRARIES} fmt nlohmann_json::nlohmann_json umskt::rc ${UMSKT_LINK_LIBS})
+
+    # if we're on 32-bit windows, add the atomic library
+    if (WIN32 AND NOT MSVC AND CMAKE_SIZEOF_VOID_P EQUAL 4)
+        target_link_libraries(umskt PRIVATE atomic)
+    endif()
+
     TARGET_LINK_DIRECTORIES(umskt PUBLIC ${UMSKT_LINK_DIRS})
 
     # Link required Windows system libraries for OpenSSL