Nicole Rauch wrote:
gc.c:2553: failed assertion `A.I.updated == A.I.i_marked + A.M.i_marked - immutable_overflow'
This looks like a memory overflow. Try to increase the proportion of the immutable area on the heap. This is done through command line options of the poly command (in your isabelle/etc/settings file). Check the poly manual for the exact options to use.