diff --git a/iprbench/envmodules.py b/iprbench/envmodules.py
index 4b692ba..2cb0a0b 100644
--- a/iprbench/envmodules.py
+++ b/iprbench/envmodules.py
@@ -22,6 +22,7 @@ def get_available_modules() -> Set[EnvModule]:
     # modules
     # null
     stdout = completed_process.stdout.decode('utf-8')
+    logging.debug('get_available_modules: stdout="%s"', stdout)
     for line in stdout.splitlines():
         logging.debug('available module line: "%s"', line)
         if not re.search(r'\:$', line):  # ignore the directories such as '/usr/share/modules/modulefiles:'