When compiling under gcc4.6+, the following errors can be seen:

[   93s] In file included from /usr/include/sigc++-2.0/sigc++/signal.h:8:0,
[   93s]                  from /usr/include/sigc++-2.0/sigc++/connection.h:22,
[   93s]                  from ../../../services/plugins/dndcp/dnd/copyPasteRpc.hh:28,
[   93s]                  from dndGuest/copyPasteRpcV3.hh:29,
[   93s]                  from dndGuest/copyPasteRpcV3.cc:26:
[   93s] /usr/include/sigc++-2.0/sigc++/signal_base.h:46:11: error: 'size_t' does not name a type
[   93s]    typedef size_t size_type;
[   93s]            ^
[   93s] /usr/include/sigc++-2.0/sigc++/signal_base.h:95:3: error: 'size_type' does not name a type
[   93s]    size_type size() const;
[   93s]    ^
[   93s] /usr/include/sigc++-2.0/sigc++/signal_base.h:239:11: error: 'size_t' does not name a type
[   93s]    typedef size_t size_type;
[   93s]            ^
[   93s] /usr/include/sigc++-2.0/sigc++/signal_base.h:261:3: error: 'size_type' does not name a type
[   93s]    size_type size() const;

As per https://gcc.gnu.org/gcc-4.6/porting_to.html, this is fixed through:

 #include <cstddef>


Index: open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/copyPasteRpc.hh
===================================================================
--- open-vm-tools-9.10.0-2476743.orig/services/plugins/dndcp/dnd/copyPasteRpc.hh
+++ open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/copyPasteRpc.hh
@@ -25,6 +25,7 @@
 #ifndef COPY_PASTE_RPC_HH
 #define COPY_PASTE_RPC_HH
 
+#include <cstddef>
 #include <sigc++/connection.h>
 #include "dndCPLibExport.hh"
 #include "rpcBase.h"
Index: open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/dndRpc.hh
===================================================================
--- open-vm-tools-9.10.0-2476743.orig/services/plugins/dndcp/dnd/dndRpc.hh
+++ open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/dndRpc.hh
@@ -25,6 +25,7 @@
 #ifndef DND_RPC_HH
 #define DND_RPC_HH
 
+#include <cstddef>
 #include <sigc++/connection.h>
 #include "dndCPLibExport.hh"
 #include "rpcBase.h"
Index: open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/fileTransferRpc.hh
===================================================================
--- open-vm-tools-9.10.0-2476743.orig/services/plugins/dndcp/dnd/fileTransferRpc.hh
+++ open-vm-tools-9.10.0-2476743/services/plugins/dndcp/dnd/fileTransferRpc.hh
@@ -25,6 +25,7 @@
 #ifndef FILE_TRANSFER_RPC_HH
 #define FILE_TRANSFER_RPC_HH
 
+#include <cstddef>
 #include <sigc++/connection.h>
 #include "dndCPLibExport.hh"
 #include "rpcBase.h"