--- a/types/scene/wlr_scene.c
+++ b/types/scene/wlr_scene.c
@@ -1,4 +1,6 @@
 #include <assert.h>
+#include <inttypes.h>
+#include <time.h>
 #include <pixman.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -50,6 +52,18 @@
 };
 static struct scene_tree_clip *scene_tree_clips;
 
+// WHY: this disposable trace aligns compositor damage and output commits with
+// runner CLOCK_MONOTONIC actions; it does not identify presented frames.
+// CONTRACT: counters are local to this private process and have no ABI/API use.
+// INVARIANT: logging does not change the clip, damage ring or output state.
+static uint64_t temporal_damage_ordinal;
+static uint64_t temporal_commit_ordinal;
+static uint64_t temporal_now_ns(void) {
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return (uint64_t)ts.tv_sec * UINT64_C(1000000000) + (uint64_t)ts.tv_nsec;
+}
+
 static struct scene_tree_clip *scene_tree_clip_find(struct wlr_scene_tree *tree) {
 	for (struct scene_tree_clip *it = scene_tree_clips; it; it = it->next) {
 		if (it->tree == tree) return it;
@@ -510,6 +524,10 @@
 		const pixman_box32_t *extent = pixman_region32_extents(&clipped);
 		wlr_log(WLR_INFO, "SPIKE_DAMAGE output=%s extent=%d,%d..%d,%d",
 			output->name, extent->x1, extent->y1, extent->x2, extent->y2);
+		wlr_log(WLR_INFO, "TEMPORAL_DAMAGE ordinal=%" PRIu64 " ns=%" PRIu64
+			" output=%s extent=%d,%d..%d,%d",
+			++temporal_damage_ordinal, temporal_now_ns(), output->name,
+			extent->x1, extent->y1, extent->x2, extent->y2);
 		wlr_output_schedule_frame(scene_output->output);
 		wlr_damage_ring_add(&scene_output->damage_ring, &clipped);
 
@@ -3077,6 +3095,10 @@
 	}
 
 	ok = wlr_output_commit_state(scene_output->output, &state);
+	wlr_log(WLR_INFO, "TEMPORAL_COMMIT ordinal=%" PRIu64 " ns=%" PRIu64
+		" output=%s accepted=%d",
+		++temporal_commit_ordinal, temporal_now_ns(),
+		scene_output->output->name, ok);
 	if (!ok) {
 		goto out;
 	}