[cifuzz] Add  feedback for bad build check (#6174)

diff --git a/infra/cifuzz/build_fuzzers.py b/infra/cifuzz/build_fuzzers.py
index 0b8f9af..126ffe9 100644
--- a/infra/cifuzz/build_fuzzers.py
+++ b/infra/cifuzz/build_fuzzers.py
@@ -204,8 +204,13 @@
     env['ALLOWED_BROKEN_TARGETS_PERCENTAGE'] = (
         config.allowed_broken_targets_percentage)
 
-  _, _, retcode = utils.execute('test_all.py', env=env)
-  return retcode == 0
+  stdout, stderr, retcode = utils.execute('test_all.py', env=env)
+  print(f'Build check: stdout: {stdout}\nstderr: {stderr}')
+  if retcode == 0:
+    logging.info('Build check passed.')
+    return True
+  logging.info('Build check failed.')
+  return False
 
 
 def _get_docker_build_fuzzers_args_not_container(host_repo_path):