Transporting core files is usually necessary to debug a core file on a system other than that which produced it. It is sometimes possible to debug a core file on a system other than that which produced it if the current system is sufficiently similar to the original system, but it will not work correctly in general.
When moving core files, don't forget to move the original executable and any shared components it required.
If the POSIX Threads Library is involved, set the LD_LIBRARY_PATH environment variable to the debugger subdirectory so that the debugger will use the correct libpthreaddebug.so.
% env IDB_COREFILE_LIBRARY_PATH=applibs \
LD_LIBRARY_PATH=dbglibs \
idb a.out core