From b953ac295ba3a83f43bfc955a56a7d73a53b239a Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 7 Nov 2017 11:36:05 +0100
Subject: [PATCH] check for built css as well in data-files lookup

avoids serving incomplete files
---
 jupyterhub/_data.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/jupyterhub/_data.py b/jupyterhub/_data.py
index c53d07d7..284005fe 100644
--- a/jupyterhub/_data.py
+++ b/jupyterhub/_data.py
@@ -13,7 +13,8 @@ def get_data_files():
         # walk up, looking for prefix/share/jupyter
         while path != '/':
             share_jupyter = join(path, 'share', 'jupyter', 'hub')
-            if exists(join(share_jupyter, 'static', 'components')):
+            static = join(share_jupyter, 'static')
+            if all(exists(join(static, f)) for f in ['components', 'css']):
                 return share_jupyter
             path, _ = split(path)
     # didn't find it, give up