[not for landing] Debugging gpu failures

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index d113221edcde594fc51a59c38d43554793b8196b..ea7897576c4a0db7b0aeeccf0ba0afe8d0f82321 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -647,6 +647,11 @@ void MarkCompactCollector::CollectEvacuationCandidates(PagedSpace* space) {
     CHECK(!p->IsEvacuationCandidate());
     CHECK_NULL(p->old_to_old_slots());
     CHECK_NULL(p->typed_old_to_old_slots());
+    if (!p->SweepingDone()) {
+      CHECK(!sweeping_in_progress());
+      CHECK(sweeper().IsSweepingCompleted(space->identity()));
+      CHECK(false);
+    }
     CHECK(p->SweepingDone());
     DCHECK(p->area_size() == area_size);
     pages.push_back(std::make_pair(p->LiveBytesFromFreeList(), p));