diff --git a/pack-objects.c b/pack-objects.c
index 523a1c7..8ff7f30 100644
--- a/pack-objects.c
+++ b/pack-objects.c
@@ -1116,8 +1116,10 @@ static void find_deltas(struct object_en
 		if (!n->index)
 			die("out of memory");
 
+fprintf(stderr, "trg %s\n", sha1_to_hex(entry->sha1));
 		j = window;
 		while (--j > 0) {
+			int rc;
 			unsigned int other_idx = idx + j;
 			struct unpacked *m;
 			if (other_idx >= window)
@@ -1125,10 +1127,15 @@ static void find_deltas(struct object_en
 			m = array + other_idx;
 			if (!m->entry)
 				break;
-			if (try_delta(n, m, m->index, depth) < 0)
+			rc = try_delta(n, m, m->index, depth);
+fprintf(stderr, "% d src %s depth %d delta_sz %d\n", rc, sha1_to_hex(m->entry->sha1), m->entry->depth, n->entry->delta_size);
+			if (rc < 0)
 				break;
 		}
+static int nbdelta=0, deltasz=0;
+if (n->entry->delta) nbdelta++, deltasz += n->entry->delta_size;
+fprintf(stderr, "nbdelta = %d deltasz = %d\n", nbdelta, deltasz);
 #if 1
 		/* if we made n a delta, and if n is already at max
 		 * depth, leaving it in the window is pointless.  we
 		 * should evict it first.