gistfile1.txt

diff --git a/src/6model/sc.c b/src/6model/sc.c
index 8ff6890..237431b 100644
--- a/src/6model/sc.c
+++ b/src/6model/sc.c
@@ -357,6 +357,7 @@ void MVM_sc_wb_hit_st(MVMThreadContext *tc, MVMSTable *st) {
      * of the compilation we're currently in. Repossess if so. */
     comp_sc = (MVMSerializationContext *)MVM_repr_at_pos_o(tc, tc->compiling_scs, 0);
     if (MVM_sc_get_stable_sc(tc, st) != comp_sc) {
+MVM_exception_throw_adhoc(tc, "oops, repossessed STable");
         /* Add to root set. */
         MVMint64 new_slot = comp_sc->body->num_stables;
         MVM_sc_push_stable(tc, comp_sc, st);