Examining a kernel crash dump with a graphical debugger like ddd is also possible (you will need to install the devel/ddd port in order to use the ddd debugger). Add the -k option to the ddd command line you would use normally. For example;
# ddd -k /var/crash/kernel.0 /var/crash/vmcore.0
You should then be able to go about looking at the crash dump using ddd's graphical interface.
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