Fix doc build if git is absent

When building packages if git is absent, then we should not set
html_last_updated_fmt. It can still be set via the -D switch
when building with sphinx-build.

Change-Id: If6585c62ed783f38b2b80afa7fc9795f7e9426a6
Closes-Bug: #1552251

1 files changed, 8 insertions, 2 deletions

diff --git a/doc/source/conf.py b/doc/source/conf.py
index e483b53..8bb3fe4 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -25,6 +25,7 @@
 
 import os
 import subprocess
+import warnings
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -149,8 +150,13 @@ html_theme_options = {
 # html_last_updated_fmt = '%b %d, %Y'
 git_cmd = ["git", "log", "--pretty=format:'%ad, commit %h'", "--date=local",
            "-n1"]
-html_last_updated_fmt = subprocess.Popen(
-    git_cmd, stdout=subprocess.PIPE).communicate()[0]
+try:
+    html_last_updated_fmt = subprocess.Popen(
+        git_cmd, stdout=subprocess.PIPE).communicate()[0]
+except Exception:
+    warnings.warn('Cannot get last updated time from git repository. '
+                  'Not setting "html_last_updated_fmt".')
+
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.