Document update for nd/unpack-trees-with-cache-tree

diff --git a/t/README b/t/README
index 8373a27fea38b1ec111e80d203bf61f1143b7861..0e7cc2373419a7297a73978e01319e8ccc23402c 100644 (file)
--- a/t/README
+++ b/t/README
@@ -315,6 +315,10 @@ packs on demand. This normally only happens when the object size is
 over 2GB. This variable forces the code path on any object larger than
 <n> bytes.
 
+GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES=<boolean> checks that cache-tree
+records are valid when the index is written out or after a merge. This
+is mostly to catch missing invalidation. Default is true.
+
 Naming Tests
 ------------