Availability:built-in
prolog_debug(+Topic)
prolog_nodebug(+Topic)Enable/disable a debug topic. Topic is an atom that 
identifies the desired topic. The available topics are defined in
src/pl-debug.h. Please search the sources to find out what 
is actually printed and when. We highlight one topic here:
- chk_secure(A)
- dd many expensive consistency checks to the system. This should 
typically be used when the system crashes, notably in the garbage 
collector. Garbage collection crashes are in most cases caused by 
invalid data on the Prolog stacks. This debug topic may help locating 
how the invalid data was created.
These predicates require the system to be compiled for debugging 
using
cmake -DCMAKE_BUILD_TYPE=Debug.