if you can, please re-compile MoarVM passing the same options that were used before (you can find them on the first screenfuls of the Makefile inside moarvm's source folder) to Configure.pl but also include --debug=3 and --optimize=0. This is an optional step. After that, please run perl6-valgrind-m instead of perl6 or perl6-m to execute your script, that should give more helpful data.
Later on, to run stuff regularly again, turn optimize back up to 3, otherwise things will be noticeably slower.