diff --git a/support/testing/infra/__init__.py b/support/testing/infra/__init__.py
index 1f003f24c6..52308395a3 100644
--- a/support/testing/infra/__init__.py
+++ b/support/testing/infra/__init__.py
@@ -59,11 +59,20 @@ def download(dldir, filename):
 
 def run_cmd_on_host(builddir, cmd):
     """Call subprocess.check_output and return the text output."""
-    out = subprocess.check_output(cmd,
-                                  stderr=open(os.devnull, "w"),
-                                  cwd=builddir,
-                                  env={"LANG": "C"},
-                                  universal_newlines=True)
+    try:
+        out = subprocess.check_output(cmd,
+                                      cwd=builddir,
+                                      env={"LANG": "C"},
+                                      stderr=subprocess.STDOUT,
+                                      text=True,
+                                      universal_newlines=True)
+    except subprocess.CalledProcessError as e:
+        print(f"Command failed with return code {e.returncode}")
+        print("=== STDOUT/STDERR ===")
+        print(e.output)
+        print("=====================")
+        raise
+
     return out