3 files changed, 26 insertions, 1 deletions

diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index b5f5f0362..878651c8e 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -4,3 +4,8 @@ clang_format = true
 [Builtin Hooks Options]
 # Handle native codes only.
 clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp
+
+[Hook Scripts]
+checkstyle_hook = ${REPO_ROOT}/prebuilts/checkstyle/checkstyle.py --sha ${PREUPLOAD_COMMIT}
+                  -fw sample_updater/
+
diff --git a/applypatch/applypatch.cpp b/applypatch/applypatch.cpp
index 6f6c187be..120add6d6 100644
--- a/applypatch/applypatch.cpp
+++ b/applypatch/applypatch.cpp
@@ -652,7 +652,22 @@ static int GenerateTarget(const FileContents& source_file, const std::unique_ptr
   uint8_t current_target_sha1[SHA_DIGEST_LENGTH];
   SHA1_Final(current_target_sha1, &ctx);
   if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_LENGTH) != 0) {
-    printf("patch did not produce expected sha1\n");
+    printf("patch did not produce expected sha1 of %s\n", short_sha1(target_sha1).c_str());
+
+    printf("target size %zu sha1 %s\n", memory_sink_str.size(),
+           short_sha1(current_target_sha1).c_str());
+    printf("source size %zu sha1 %s\n", source_file.data.size(),
+           short_sha1(source_file.sha1).c_str());
+
+    uint8_t patch_digest[SHA_DIGEST_LENGTH];
+    SHA1(reinterpret_cast<const uint8_t*>(patch->data.data()), patch->data.size(), patch_digest);
+    printf("patch size %zu sha1 %s\n", patch->data.size(), short_sha1(patch_digest).c_str());
+
+    uint8_t bonus_digest[SHA_DIGEST_LENGTH];
+    SHA1(reinterpret_cast<const uint8_t*>(bonus_data->data.data()), bonus_data->data.size(),
+         bonus_digest);
+    printf("bonus size %zu sha1 %s\n", bonus_data->data.size(), short_sha1(bonus_digest).c_str());
+
     return 1;
   } else {
     printf("now %s\n", short_sha1(target_sha1).c_str());
diff --git a/tests/component/applypatch_test.cpp b/tests/component/applypatch_test.cpp
index aa0959bf5..f19f28c60 100644
--- a/tests/component/applypatch_test.cpp
+++ b/tests/component/applypatch_test.cpp
@@ -344,6 +344,11 @@ TEST_F(ApplyPatchModesTest, PatchModeEmmcTargetWithMultiplePatches) {
                                     patch1.c_str(),
                                     patch2.c_str(),
                                     patch3.c_str() };
+  // TODO(b/67849209): Remove after addressing the flakiness.
+  printf("Calling applypatch_modes with the following args:\n");
+  for (const auto& arg : args) {
+    printf("  %s\n", arg);
+  }
   ASSERT_EQ(0, applypatch_modes(args.size(), args.data()));
 }