Improve debug output of the build_docs script

Only log if there was output, and convert the binary string to
Unicode string.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/scripts/build_docs.py b/src/scripts/build_docs.py
index 5d7181dec..94c61afdf 100755
--- a/src/scripts/build_docs.py
+++ b/src/scripts/build_docs.py
@@ -62,8 +62,11 @@ def run_and_check(cmd_line, cwd=None):
 
     (stdout, stderr) = proc.communicate()
 
-    logging.debug(stdout)
-    logging.debug(stderr)
+    if stdout:
+        logging.debug(stdout.decode())
+
+    if stderr:
+        logging.debug(stderr.decode())
 
     if proc.returncode != 0:
         logging.error("Error running %s", ' '.join(cmd_line))