Solution for “org.eclipse.cdt.dsf.gdb [3.0.0.201102110609] could not be found”

When updating CDT, I got the following error: Cannot complete the install because one or more required items could not be found.
Software being installed: C/C++ DSF GDB Debugger Integration 2.1.0.201102110609 (org.eclipse.cdt.gnu.dsf.feature.group 2.1.0.201102110609)
Missing requirement: C/C++ DSF GDB Debugger Integration 2.1.0.201102110609 (org.eclipse.cdt.gnu.dsf.feature.group 2.1.0.201102110609) requires ‘org.eclipse.cdt.dsf.gdb [3.0.0.201102110609]’ but it could not be found
Google just told me to use the official CDT update site, but it is already in use for my case.
Solution:
copy D:\apps\Helios\cdt\plugins\org.eclipse.cdt.dsf.gdb_3.0.0.201102110609.jar from another instance of CDT into D:\apps\IBM\SDP\dropins\org.eclipse.cdt.dsf.gdb_3.0.0.201102110609.jar. Then CDT is updated successfully.