As of CDT 9.0, the support for the obsolete Apple GDB has been removed. As an alternative, the GDB from the FSF (Free Software Foundation) can be used. Some instructions on how to do this are available on the CDT FAQ page
As for CDT 9.0, the CDT will strive to officially adopt MSYS2 as a supported platform for Windows, and Homebrew as a supported platform for Mac.
As a direct answer to requests from our user forum, CDT 9.0 includes a Mac version of the C/C++ RCP Stand-alone debugger.
The QNX and AI64 targets have been removed from CDT 9.0. These are not supported by the platform and therefore, no longer needed to be supported by the CDT.