Yes, there does seem to be an issue here. We'll look at fixing this in a future product release, but in the meantime, you can achieve your requirement in one of the following two ways...
In the case that you have a project which does not yet have a launch configuration file (or where you are happy to delete the existing launch configuration file), then the simplest way to solve this is to go to:
Preferences - LPCXpresso - Debug Options (Miscellaneous)
and change the Debugger Executable from "arm-none-eabi-gdb" to "arm-none-eabi-gdb-py". This setting will then get picked up when you first debug your project (when the IDE will automatically create a new launch configuration file).
Or to update an existing launch configuration, double click on the .launch file inside your project (in the Project Explorer view) to open it in the editor. Then change the line:
<stringAttribute key="org.eclipse.cdt.dsf.gdb.DEBUG_NAME" value="arm-none-eabi-gdb"/>
to
<stringAttribute key="org.eclipse.cdt.dsf.gdb.DEBUG_NAME" value="arm-none-eabi-gdb-py"/>
Regards,
LPCXpresso Support