There is an issue reported when building AG debug kernel. The root cause to the issue was about adding ssl3_ciphers.o object file to a not existed but hard code path. 
I have modified the hard code part of the path to a variable $(CLICK_KERNEL_CONFIG) in three files, and compiling error triggered by "make nodebug-package" command is fixed. 
However, there is another hard code path created for scenarios that the variable is not defined when executing command "make install-userland" only.

I have successfully built AG debug kernel and confirmed the debugging symbols were attached to the kernel. When using the debug kernel, AG is able to use kgdb to debug core dump files.