block on installing node packages

Author: bollwyvl

docs/conf.py

@@ -105,4 +105,4 @@ def setup(app):
     """ Runs before the "normal business" of sphinx. Don't go too crazy here.
     """
     app.add_css_file("css/custom.css")
-    subprocess.Popen(["jlpm", "--ignore-optional"])
+    subprocess.check_call(["jlpm", "--ignore-optional"])