https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89179
--- Comment #16 from Steve Ellcey <sje at gcc dot gnu.org> --- I built ggc-page.c with GCC_DEBUG_LEVEL 5 and I see: Allocating object, requested size=360, actual=360 at 0xffff8726c210 on 0x10549200 Freeing object, actual size=360, at 0xffff8726c210 on 0x10549200 But then I wind up calling gt_ggc_mx_symtab_node with x_p of 0xffff8726c210. I don't think I should be calling this (via ggc_mark_roots and ggc_collect) if it has already been freed.